That account migration sucks bigtime. I had to do it for my account and all of my kid's accounts and every single time it was a chore. You aren't signing up for a "Microsoft" account, you're getting an account on like 4 different services that don't talk to each other. Then you have to dig way deep in the settings on one of the services to find the poorly labeled switch (I believe it says something like "allow online chat") that allows the accounts to connect to my local server.

Even more fun for me: The email address I had used to create the Mojang account had long ago been registered by some bot on the Microsoft side. So I had to do an account recovery/takeover in order to do the migration, but it turns out you can't completely switch the language settings so even though the web pages are in English any email from Microsoft comes in German. There's also the possibility that the bot will take the account back at some point, even though I've tried my best to change all of the information in it and I own the associated email address. I'm actually pretty annoyed that Microsoft let the bot register it without ever verifying the email. Also, it gave me a super lame XBox handle and I can't seem to change it.

The old Mojang account was way easier to use.

The only thing worse is when Oculus forced everybody to make new accounts for the headsets to be more (or less?!?) Facebook/Horizon Worlds tied. That was an even bigger headache.