My familiarity with Flashpoint mainly comes from the animated movie (which I haven't seen in years) and The Flash series. Figured it was probably something like that. Even ripping through time, I'm confused about how that brings in Bruce from Earth-89, but I guess you just got to roll with it.Funny enough, I know how THAT works.
In the comics, Flashpoint rippled through time in both directions - past and future - because Barry absorbed too much of the speed force.