I do not think that a surviving Yugoslavia is as radical a proposition as some had suggested in this thread. Of course, there are ways of dealing with some of the country's chronic issues far earlier (as I had discussed before), but let's consider what some might call the latest possible PoD that could preserve Yugoslavia: the 8th Plenary Session of the Central Committee of the League of Communists of Serbia, September 1987.
The simplest PoD one could invoke here is having then-President of Serbia Ivan Stambolić not send out the letter he had sent asking the members of the party's Belgrade branch to stay out of the discussion if the question was raised on expelling ally and branch leader Dragiša Pavlović from the party. The letter was seen as overly pressuring by party members, with Milošević's supporters being particularly angry at it. In the lead-up of the session, on the 18th of September, Stambolić tried to forge a compromise, but by this point Slobodan Milošević had fully publicly turned on Pavlović, but he could've been fully outmanoeuvred in that scenario by Stambolić, if not for his allies revealing the letter to Milošević. The next day, to the shock and horror of those present among the party, Milošević read the letter, and produced another claiming it to be proof of Stambolić putting personal interests ahead of those of the party. By the time the session itself occurred on the 22nd, the cards had been stacked against Stambolić, and would ultimately result in Pavlović's expelling and Stambolić's resignation.
With the letter butterflied, Milošević's OTL meteoric rise gets kneecapped, and the infighting within the Serbian branch of the party is contained for now, giving everyone involved more time. Some, such as
Radoje Stefanović (at the time President of the Chamber of Commerce of Serbia), have discussed how, parallel to all this, Stambolić was leading with his side discussions on constitutional amendments, ones which the Kosovar leadership had agreed on, but not the Vojvodian leadership yet. Due to the apparent power struggle going on though, as he would say, "However, the Eighth Session came at which there wasn't a single word on it. It was a taboo topic. The fact that negotiations were underway and that amicable solutions were being reached in them was irreconcilable, rather it was necessary to 'fight for the Serbs'." TTL's 8th Plenary Session might see these aspects, among others, actually discussed, all the while Milošević may put himself on the back foot further, the nationalists assured that actions can only be taken through discussion and compromise (which they are forced to accept grumbling).
Concurrently, Milošević was already working on gaining control over the media for the purpose of spreading nationalism (which already prompted Stambolić to try and get him replaced), even if Serbian leadership was sympathetic to the plight of Serbs in this period. With his misstep at the 8th Plenary Session, he may try to shift toward further media control, trying to achieve the creation of what he had done OTL with the centralizing of Radio Television Belgrade with Radio Television Novi Sad and Radio Television Pristina to create Radio Television Serbia, which may end up being such an overreach that a session is called. Mirroring the downfall of Aleksandar Ranković to some extent, Milošević is called to be dismissed from the Communist Party, have his control over party and state assets dismissed, and to be prohibited from participating in public functions. The Nationalists, reminded of Ranković, attempt to protest, but most are forced to agree that Milošević had gone too far. Depending on what private discussions are had post-session, Milošević may even depart Yugoslavia in exile, along with his wife Mirjana Marković and son Marko, likely in search of new allies.
Milošević’s former allies waver, as they fail to rally around another figurehead as Milošević had been, and the other republics of Yugoslavia breath a sigh of relief that affairs in the Serbian party had calmed, with dialogues between them continuing in hopes of reaching a consensus on what to do next, along with figuring out what the Vojvodian leadership (still thinking themselves above Belgrade's affairs) wants. Eventually, a new constitution for the Socialist Republic of Serbia is invoked, having roughly achieved what they wanted (including Vojvodina and Kosovo maintaining their special status and ethnic autonomy, agreeing to bind themselves to Serbia on their own terms) and satisfying leadership. The Serbian National Assembly would, however, likely see a divide in the form of, uh, let's describe it as Serbian patriotism and overt Serbian nationalism, with the former being more conciliatory and willing to compromise, and borrowing more from Stambolić and Pavlović, while the latter is a mix of Sloba's former allies and more overly nationalist figures, and becoming a sort of eternal opposition whilst struggling to some degree to rally around someone with the power vacuum (at least, until reforms permit for the rise of non-Communist parties). There'd likely still be much nationalism in the south of the country with Kosovo, but border liberalization with Albania could help solve some issues, allowing die-hards to leave the country, along with whatever Kosovar leadership had gotten Belgrade to agree to. If the 1997 civil war in Albania happens still, we could see some of the folks associated with the OTL Democratic League of Kosovo and Kosovo Liberation Army take part as to ensure that whatever Albania comes out in the end, it is one able to advocate for a greater Albania.
The ramifications of Yugoslavia's survival are still significant, don't get me wrong. Upward of 140k people don't die, some 4 million don't get displaced, and who knows how many others were impacted by the economic troubles of the time, prompting immigration. The infrastructure and industries of the republics remain intact, which is especially impactful for Serbia. Some of the OTL developments within the socio-political scenes in Bosnia and Croatia get butterflied, Bosnia continues on as it had rather than adopting the system it had post-Dayton, and Yugoslavia remains the one European case outside the hold-held principle of Ethnic National Sovereignty, assuming the Soviet Union still collapses. Internationally, many of the lessons that had been learned from the conflict, by the United Nations (especially when it comes to safe zones, i.e. Dutchbat), by NATO, etc. are butterflied. There would be absolute shockwaves from this, where we
don't see scholars falling back on lazy arguments of Yugoslavia falling apart due to "ancient hatred," and terms such as balkanization don't see a prominent second lease on life.
Personally, I don't think Yugoslavia would be part of the EU, but could perhaps be in the same position as, say, Switzerland or Norway, and be part of the few other trade agreements/organizations on the continent - perhaps the European Free Trade Association, or more fitting, the Central European Free Trade Agreement. Due to its nature as one of the few non-ethnic states of Europe, some degree of "on the outs" would likely be present, but I imagine there'd be a transition to democracy comparable to other post-communist states that had since joined the EU. It'd likely have strained relations with Albania and Bulgaria for nationalistic reasons. In regards to internal politics, since I would imagine many within the diaspora coming to Yugoslavia post-political liberalization as to vote out the communists, and likely seeing the rise of nationalism still, I suspect we could see an internal dynamic comparable to that of OTL Bosnia, which has the leaders of the three nations riling up their constituents to ensure their continued support, whilst behind the scenes just working out deals easily.
