@ned
Yeah - they have done that for years now. There are slight differences between the two games - like some unique Pokemon in each game.
IGN has a long story listing the differences
https://www.ign.com/wikis/pokemon-sword-shield/Pokemon_Sword_and_Shield_Version_Differences_and_Exclusives
I had two boys so we would buy both anyway so they could swap between games and get more Pokemon.