The trade system and Pops are two things off the top of my head that set it apart from EU4. It’s not trying to be CK2, but characters also play a more prominent role. Popular generals can be dangerous, as are powerful governors and the like. Warfare sounds like it has more granularity than EU4 does as well. There’s a lot more to army composition which varies between cultures as well as military tactics you play.
Of the various Paradox games I think it will be closest to EU4 but I think there’s enough differences in core systems to make it feel distinct. I’ll have to wait and see, though!