Detailed Xbox Opt Out Steps
Open the Xbox Insider Hub app and unenroll from the beta.
Uninstall Minecraft.
Hard reset the Xbox console by holding down the power button until the console turns off, wait 10 seconds, then turn the console back on.
Reinstall Minecraft from the Ready to Install section of Games & Apps.
https://feedback.minecraft.net/hc/en-us/articles/360004438671-How-to-Join-and-leave-the-Minecraft-Beta
Sven Pettersson
Detailed Xbox Opt Out Steps
Open the Xbox Insider Hub app and unenroll from the beta.
Uninstall Minecraft.
Hard reset the Xbox console by holding down the power button until the console turns off, wait 10 seconds, then turn the console back on.
Reinstall Minecraft from the Ready to Install section of Games & Apps.
https://feedback.minecraft.net/hc/en-us/articles/360004438671-How-to-Join-and-leave-the-Minecraft-Beta