Yes, 'Minecraft' is cross-platform — here's how to play with your friends on any system

"Minecraft" offers cross-platform play for both versions of the game — Bedrock and Java — but you can only play with users ...
PCGamesN

Minecraft: Java Edition locks out old accounts in March

Way back in 2020, the developers announced a major change to Minecraft: Java Edition, as players would soon be required to swap from a Mojang account to a Microsoft account in order to keep playing.

How to change your Minecraft username in every version of the game

There are a few different ways to change your Minecraft username, but most users will do it through the Xbox website.
Neowin

Minecraft Java Edition players must move to Microsoft accounts by September 19Minecraft Java Edition players must move to Microsoft accounts by September 19Minecraft Java ...

Back in 2020, Minecraft developer Mojang announced that players of the Minecraft Java Edition would need to migrate their old Mojang accounts to Microsoft accounts if they wanted to keep playing that ...