I limited it to two for simplicity, but sure, you had many options for your breakfast choice this morning, only the universe in which you made the right choice did you survive.
Thanos is child’s play. He only wiped out half the universe, once. The TVA routinely eliminates entire universes. I can’t help but feel that they are the real villains in this story.
It does make me wonder if it is a quantum multiverse type thing where trillions of choices are made ever femtosecond, with only one choice being allowed to continue, or if only powerful people or powerful objects can divert the timeline enough for the TVA to intervene.
There does seem to be continuity and causality to the timeline within the TVA. Möbius does say that time doesn’t work the same way as on the outside when asked how long he had been there, but he didn’t really explain how it works either. Are they not able to move to other points in the TVA timeline, or they just choose/are ordered not to?
But, just as you and I do not know the future of our own timeline, while some hypothetical time agents would, the TVA may not know their own future, even though those above them may.