Doesn't the Sundering always happen regardless of whether we go back in time or not? I'm not completely convinced we changed much. I was under the impression that we may have changed a teeny bit of the background of events, but they would have happened anyway. The biggest evidence of this is that in the original, untampered timeline that G'raha came from, Hydaelyn still exists and everything still happened despite the WoL dying to Black Rose so they never time-traveled.
Even without WoL in Elpis, Emet-Selch and Hythlodeus meet with Hermes who gets upset about taking over Fandaniel's seat and needs time to think so they wander around and explore Elpis and bump into Venat until Meteion gets her report. The parts WoL influenced were spending time with Meteion so she wasn't lonely and wasn't constantly suffused with Hermes' bad dynamis, Hermes never finding out that other people are sad, the Crew never finding out about our past and their future, and an extra helper being present in order to corral Meteion.
I came out of Endwalker thinking that we just gave Venat a different reason or more clarity to do what she would have already done to begin with.
The biggest effect our time-travel shenanigans have is after we have already done it: familiarity with Hydaelyn when we meet her, and Meteion is marked and we know where she is, what she is, and why she needs to be stopped, which is why we went to Elpis in the first place.