we'll probably see rebellions based on ideology and opinions... you anger some of them to much and they will try to overthrow you or get independend like in all games
i would think that as soon as you integrated multiple races and evolve multiple ideologies in your pops you will anger one or the other if you concentrate to much on one part... e.g. war, trade, diplo..
also based on the size of your realm, people living far away want their own realm and not pay taxes to you.. or they get harrassed by pirates and you don't have enough ships in that part of the universe etc. lots of possibilties for them to become unhappy....
of course i fear that that game becomes like euIv late game where you just ship your troops from one part of the world (universe) to the next one to crush stupid rebellions
but let's see how paradox will implement it this time.. i hope due to the fact that we all live in a high technical future it should be possible for those rebells to coordinate with other unhappy rebells to create multiple rebellions at the same time if you anger them all...
btw. i read about this lately in some german scifi series called SPQR - Der Falke von Rom.. i don't know if it's availabe in english yet not how it's called there.. but in this series the different cultures of earth colonized different areas around Sol and where "united" under the so called hegemony but still they maintained their culture etc..... after several time the major powers in this hegemony got angry about not being able to spread out as they wanted (e.g. invade the smaller nations).. so the different ideologies, religions, cultures etc. combined their different strenghts to force the hegemony to let them go... afterwards and some years later of course they all fight against each other.. i like this approach.. there are also interesting ideas about boarding enemies, how to deal with them etc. different ideologies have different strategies and they also have different opinions with glassing planets
