When did they ever significantly update an already-sold game, beyond bugfixes? If anything, access to the full dex through transfer might become the main selling point for the next set of games, but SwSh will probably be completely devoid of the unlucky ones forever.My guess is that they'll have to add in an all inclusive Pokemon transfer at some point(look at X/Y where we had to wait on Pokemon Bank) in the game's lifespan, and it might just be that they haven't worked out the cross-compatability feature to get the transfer done.
Wonder if this culling will also include moves. Sure, few of us will miss Rototiller, Hold Hands or Barrage, but some staple moves could be gone too. I guess we'll just have to wait and see.