All we know so far about catalysts is that Qui-Gon didn’t die. From that, we can directly extrapolate that this was what led Dooku to not Fall and leave the Order. 

Palpatine is still around, and it’s heavily hinted that he’s still Sidious (since he was able to negotiate a stand-still with the Separatists), but there’s no clues about his Apprentice. It’s possible that there’s no Maul, which led to Qui-Gon’s survival, or Maul hasn’t yet been deployed against the Jedi. If there’s no Maul, that begs the question who Sidious’s Apprentice is (if he has one at all). For all we know, the butterflies could go far back enough that Darth Plagueis is still alive and [i]Sidious[/i] is the Apprentice.

The clone army is still here, which means Sifo Dyad was probably still involved, got Jango Fett DNA, went mildly insane and made a whole-ass army behind the Republic’s back that they didn’t even know they owned somehow. His fate is uncertain, but since Dooku isn’t involved enough to spare him, Sidious probably killed him.

I am curious in particular what this universe’s inciting incident for the Clone Wars was though… as well as what happened in their Battle of Naboo.