I think we might want to consider a positive side of extended colonialism/commonwealth formation from the colonized side too. Astrodragon gave us an inverted example of what colonialism meant generally when it was pointed out that OTL, with people other than Alexander and Park in charge of the defense of Singapore and Malay peninsula, important defense works (in this case, improved airfields) were deferred because the colonial elites did not want to see the price of labor raised by the government offering the job to the local workforces!

In this timeline, Singapore is holding so far in part because its ITTL commanders would not hold with this nonsense, went ahead and hired the workers and built the fields. This is presumably one of dozens, hundreds, or perhaps thousands of instances of what was terminally
wrong with the colonialist regimes being tossed overboard in the interest of general defense. Native forces are presumably being raised, European and "white" Commonwealth forces are increasingly fighting alongside them; both sides are coming to appreciate how much they need the other. This alone will hardly eliminate all grievances but if the whites, recognizing as Park and Alexander did that they are all in this together, start acknowledging and addressing these grievances, and get increasingly used to the idea that the postwar regime will be a partnership, not a top-down master/subject relationship, then quite conceivably the notion of a return to the pre-war status on a macro scale but with much stronger native autonomy and representation in the European halls of power will not seem so bad. If wartime investment on their soil, for the sake of winning the war, transitions over to a level of investment in developing the colonies not just for European profit but for the manifest good of the colonized peoples themselves, and largely under their own direction, then many colonized peoples might see the departure of the Europeans as something to be avoided or at least delayed. It seems likely that there will still be a strong movement toward autonomy and a lot of outright nationalism that looks forward to total independence, but with the balance of sentiment shifted toward some level of relationship with the European "mother" country something more like the British Commonwealth rather than total independence might still be the norm in the 1960s; if it lasts that long, then the relationship will probably come to seem more and more normal and natural to both Europeans and their former subjects.