A few names that came to mind:
Antheria
Gravitas
Singufal
Quanim
Varioma
Shaien
There is even a possibility, that if the residekts of our time are aware of thr alternate timeline, they could give it a sort of spacetime coordinates instead of a real name. Somethig like DAT00829P51TR1. The longer versionof the afformentioned would be Discovered Alternative Timeline 00829 Phasedissynchrony 51 Time relation 1. The phasedissynchrony (which I came up just now) discribes the distance between our persieved reality towards theirs in a weird quantum resonance. Timerelation describes their timelines distance from us in Higgs Bosons spin, when it has reached quantum superposition and able to produce mass for a particle in any state or time.
These are just the things that came to me now. I hope it helps you in some way.