Account Migration has not begun. There will be an in game message when it's your turn to move. Do not fall for any third party websites that are telling you to migrate NOW. They're trying to steal your information.

Hey Monang there is a problem on Minecraft bedrock on the Xbox One where I can’t sinc old worlds from Xbox one edition to the new version because every time I try to sinc an old world from the Xbox one edition to the new version of Minecraft it crashes please fix this issue!