But Mirror Darkly need not be correct in the exact year at this point.
It’s established now that there have been successive incursions in the timeline. Time has been resistant to forks that eliminate major events entirely, but the years in which any given major event took place may shift.
If it gives TNG Berman-era fans of Picard season three comfort, this explanation can account for how Jack Crusher was both born after Nemesis and is 23-24 years old in 2401. That is, there occurred a subtle shift in the timeline between Nemesis and Picard such that Nemesis took place a few years earlier than originally.
Again, these are not the ratcheting changes of 12 Monkeys, they are eddies in the river of the Prime Timeline that shift the flow a bit but the major points of its route remains the same.