Looks like for the Communist path the name of the non-Stalin faction has been changed from "Pan-Slavic" to "Pan-Balkan" and now gives you the options to invite Greece, Romania, Hungary and Turkey in addition to the Bulgaria anad Albania focuses which were essentially worthless in DOD. This should actually make it worthwhile going down a non-Stalin path. There doesn't appear to be a focus to integrate them all into the Balkan Federation like some of the new trees, though I suppose it may possibly be done via decision.
The western focus appears to be split out even further to "Attract Axis capital" and "Attract Allied Capital" . It is really difficult to read the rest of that section of the tree but it looks like additional ways to get rid of some of the debuffs as well as further interaction with other Balkan countries. There is almost certainly a connection between the Macedonian Opposition and decisions taken by Bulgaria.
Really happy they have reworked the tree as part of this country pack as I love playing as Yugoslavia and obiously they interact with the new trees in many ways so it makes sense. I would have liked to see a more comprehensive rework but to be honest this was more than I was expecting.