Players in Pokémon Sword will see Gigantamax Flapple and Coalossal spawning more often in their raid dens, where players from Pokémon Shield will see Gigantamax Appletun and Lapras more often. Both games will have Gigantamax Alcremie spawning more frequently.
If you only have one version of the game, don’t fret — you can still participate in the other game’s Max Raid Battles through the Y-Comm, locally or through the internet, if you have a subscription to Nintendo Switch online.
It was possible to get these special Gigantamax Pokémon before, but they spawned a much lower rate. Gigantamax Corviknight, Centiskorch, Butterfree, Sandaconda, and Drednaw, which had higher spawn rates since the games’ release, now spawn at a rarer rate.
This likely means that the other rare Gigantamax finds, like Machamp and Gengar, will be featured in coming months after this rotation ends. There’s been no announcement so far when this rotation will end.
During a Pokémon Direct this morning, The Pokémon Company announced two expansions for Pokémon Sword and Shield: The Isle of Armor and The Crown Tundra. A lot of new stuff is coming with the paid expansion pass, including more Gigantamax Pokémon, including for Sword and Shield’s three starters.