Barry had met and interacted with himself a number of time without a time Quake. Heck wasn’t there like three or four Barry’s at Nona’s murder at one point? Young Barry, season one Barry, future Barry fighting Eobard, and season two Barry changing it all. So many Barrys at Nona’s murder I go cross eyed lol.
The Legends all went to collect their child selves to save them without any problem at ALL. Remember two Sara on scene at once. The time masters were cleaning that up or fixing it because they wanted them all dead so no excuse that way.
Proof once again Legends don’t really have consistency you just have to go without what story they are telling this week or choose not to because they can’t keep their ducks in a row. Dinosaurs in LA baby! It doesn’t affect anything on the other shows.