Minecraft Players Will Lose Access If They Don't Migrate Accounts

Mojang says the migration is to ensure player "security and safety." Plus, you get a free cape. 

Migrated my Mojang account to a Microsoft one and now I can't access my skins or singleplayer/multiplayer. All I'm getting is the 'Play Demo' option : r/Minecraft

Been playing since alpha - Wtf is this? : r/Minecraft

Minecraft gives final warning about losing your account

Microsoft Insists Minecraft Players Migrate Their Accounts

Minecraft Players Will Lose Access If They Don't Migrate Accounts

Minecraft: Java Edition Login Issues FAQ

why would they do that : r/MinecraftMemes

How to reactivate my mojang account after migrating it to Microsoft - Quora

Minecraft guide: How to migrate your Mojang account to a Microsoft account