What's fixed

You'll notice better handling of throttling when using Copy structure to migrate a modern site in Microsoft 365.

Customized views would get migrated when using Copy structure and Copy customized forms and views was not checked in the options.

Your migrations using Copy Content with Excel in Insane mode would not start in Microsoft 365.

You would get repeatedly prompted for credentials when adding a Microsoft 365 connection to Explorer from a connection window in migration (checking Add connection to explorer) using browser authentication.

You would get an error when reusing a connection with the Add-SiteCollectionAdministrator command in PowerShell.