I don’t think it was really retconned per se, but they did refactor the warp scales throughout that time. Like Warp 4 during Archers time may have been slower than Warp 4 during Kirk’s era, which itaelf may have been slower than Warp 4 during Picard’s.
Let’s not forget Julian who was kinda loving on Jadzia, who had been married a dozen times before, but she was never into him and then she ended up marrying Worf (who was caught in his own love triangle on his previous posting with Deanna and Will [who banged anything with at least 2 legs]) but then Jadzia died and Dax swapped bodies with a younger quirky elf who got a little side action with Worf and fooled around with Julian…