Noticed when doing a personal project with Yggdrasil auth that, despite the session server still accepting tokens you create with the Mojang auth endpoint for non-migrated accounts, all endpoints on "http://api.minecraftservices.com" don't accept it as a valid token and return a 403. You can still login to servers with these accounts, but endpoints such as "https://api.minecraftservices.com/minecraft/profile" fail to return any data which does break some software that hasn't updated yet.

The endpoint appears to be referenced on the official http://Minecraft.net site by the MSAProfileStore.ts class, which makes me believe it's a bug that it's not working and not a result of the recent Microsoft migration.

Appears to be a recent thing as these endpoints were working in the last 48h from my testing. Generated a fresh access token and ensured it was valid to verify this using the validation endpoint with a non-fixed client token.