Change can change but it is a matter of maintaining order because otherwise chaos can destroy everything and something like a person's past, if it is...
The ship will never be fully sailed but no I don't think it will come up outside of some attempt to reinforce Betsy and Rachel, but no X pairing date...
The Jubilee/Sunspot stuff, not the whole episode. It benefited by being paired with Life/Death Part 1 which advanced Storm's arc which ties into the...