On Dynamics 365 Business Central version 19 if Cloud migration is enabled the scheduled Update failed (as it is described in the official documentation.
https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/administration/migration-tool#the-set-up-cloud-migration-assisted-setup-guide )

However some partners have performed cloud migration an year ago and they have never disable cloud migration, because they never thought it is needed and they have completely forgot this fact, so when the update failed they have no idea why.

For this reason it will be good idea the partners to receive information why this update failed in mails they receive or in the Administration center.

Also it will be good if after some time the cloud migration disable itself automatically, cause no migration will be more than a 24 hours.