I think the same problem arises for some empirical questions too—T1 and T2 can be questions like “is iron’s atomic number 26 or 27?” I would have been roughly 50-50 before looking it up, but I’m uncertain if I should try to cooperate with people living in worlds where the atomic number of iron is 27 - I don’t know if those worlds are compatible with life.
Minor: The question about whether those worlds are compatible with life seems like a logical rather than empirical question to me. So this still seems like an issue with logical updatelessness rather than empirical updatelessness.
Minor: The question about whether those worlds are compatible with life seems like a logical rather than empirical question to me. So this still seems like an issue with logical updatelessness rather than empirical updatelessness.