anyone? I'm kinda struggling in this part of the planning in my TL.
I'm no specialist on Asia or Africa, but I'd proceed with three broad principles in mind.
1. Throughout much of the global south, disenfranchised intellectuals and radicals have often turned to either Islamism or Marxist-Leninism. In this scenario, there will be no Comintern as even if Italy goes leftist, any
hint of exporting the revolution is going to be clamped down on quickly by Vienna and Paris. Italy is not Russia- foreign intervention is much easier. Your Bulgarian scenario is not far of the mark. But also of note is that the Soviet Union showed that there was a path to modernity even for a semi-industrialised, ethnically heterogenous empire like Russia. Its model of development was thus very attractive to colonial nationalists.
Here, the Ottoman revival- and the continued existence of the Caliphate- is going to provide a whole new intellectual model. I would expect that plenty of radicalised young thinkers from across the Islamic world will find much to inspire them. It would not surprise me to find Tan Malaka is serving in the Ottoman Army in this timeline, perhaps reading all the Socialist Party literature he can get his hands on.
2. The Ottoman position of being neither European nor Asian, neither white nor non-white, is going to have interesting effects as well. Their success is a challenge not just to white supremacy but also to the popular idea of the time that ethnic homogeneity and racial purity was a marker of strong states- a position strongly held, of course, by many colonial nationalists (not all of them, but they certainly played a key role in, for example, Japan.)
They will represent a problem that has to be dealt with by intellectual movements of all stripes- they challenge the left's models of political development, for example.
It's possible that you see people like W. E. B. DuBois coming to write about the Ottoman revival and how that works as a model for African Americans.
3. That being said, do not overplay the desire of the actual Ottoman governments to encourage decolonisation. Some members of the Ottoman parliament will probably be interested in ideas like Pan-Turanism or even broader Pan-Asianism. But the Ottomans, like Japan, were both a colonised
and a colonial power. Your comment that France and the Ottomans won't get along when decolonisation happens is possible, but it's also possible that the Ottomans actually try to minimise the help their citizens are giving to anti-colonial movements- because the Ottoman government does not have perfect information about its own subjects, and has no way of knowing for sure that just because it seems to have settled the problems of nascent Arab/Assyrian/Balkan nationalisms that they'll stay settled if there's another great flowering of national sentiments.