I can confirm that there are naval invasions when playing with Alx. exe.I just had Qarthadastim landing full healthy stack (1600+ men) in Sicily, and KH tried to land earlier in Taras. And i noticed some other ones to.

I found that difference from BI.exe is that naval invasions are not that frequent and annoyingly stupid (like 3 units).

Even though they are rare and usually happen later in game (like 30-40 years into it or whenever they run out of rebel neighbors), they do appear to be well directed and prepared.

Plus they do make sense( at least to me) , since AI faction is trying to invade something that is part of their VC, and not some random places.