Hello Admin - Patricio Keilty,
Thanks for your question.
Yes, it is safe to delete Migration related resources.
It is recommended you verify, that it was completed properly however before proceeding.
https://learn.microsoft.com/en-us/azure/migrate/how-to-delete-project
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola