Saw someone on Twitter ask if the three most recent Star Wars movies are even a trilogy.
It's a fair question.
Yes, they involve many of the same characters. But is there an arc? Is there a coherent narrative? Is the central character the same in each one?
It certainly does not seem to be the case that there are consistent themes or ideas communicated across all three movies.
I still haven't seen TROS, but from everything I've read it seems as though these are really just three distinct movies, almost like separate seasons of a television show, that happen to be set in the same timeframe in a particular universe with a (mostly) shared set of main characters.
The coherent theme of the trilogy is trying to clumsily remix the original trilogy in a way that's at least as monetizable. That's pretty much it - slightly to moderately tweaked and rearranged elements and events with the original trilogy characters as wise old guides for the new ones. Right up to MODERATE BUT OBVIOUS SPOILER HIGHLIGHT TEXT
suddenly trotting out the Emperor as the Last Boss of Star Wars again.
The only one that really ever tried to be something more than that was Last Jedi, and it only did that sporadically and fans mostly hated those parts.
It felt kinda like one of those "we showed a machine learning algorithm the old movies and told it to write a new set" things you see sometimes. Enjoyable moments were almost all callbacks and the plots mostly seemed like a loose roadmap to get to those references and remixes.
I haven't seen 9 yet, but from what I've read it seems like the 3 movies are about Kylo and Rey jointly. Again I haven't seen 9, but the first two were definitely about their competing though connected story lines.
I can see how that may have been the general idea, but I dont' know if there was a consistent thread from TFA to TLJ, and nothing I've read about TROS suggests that it's been clarified in the most recent episode.
It's definitely clarified and made really really explicit in the new one, just in kind of an abrupt and hamhanded way. But they make a point to tell the audience "here's why these two are special and connected" and thematically it's hammered a lot as well, especially late.