It's certainly some of those things!
DLC tied to 3rd party IP (bonus advertising!):
https://www.minecraft.net/en-us/article/batman-dlc-swoops-mi...
https://www.eurogamer.net/dungeons-dragons-dlc-heading-to-mi...
Limited time events with exclusive content to make kids feel like shit if they don't/can't login at certain dates/times:
https://www.minecraft.net/en-us/article/discover-summer-cele...
https://www.minecraft.net/en-us/article/star-wars-celebratio...
In-game ads:
https://www.blockchaingamer.biz/news/16967/relentlo-brings-i...
It's unclear to me if any of their events or DLC includes loot boxes (mere chances to acquire certain content) or not. if they haven't done that, I give them credit
I'm also not sure how much direct advertising Microsoft does in-game. Have they worked with ad companies like this to promote third party or non-game content? https://www.adweek.com/creativity/minecraft-built-a-colossal...
I'm sure it's not as bad as Roblox or Fortnite but Microsoft does not have clean hands here either.