Currently, personal Forms are not backed up/recoverable.
As with any other content a user creates (email, chat, OneDrive, etc..) Forms should be included in the data captured and recoverable/restorable.
Thanks for bringing this to our attention from your side. I have already passed this feedback to our Product Feedback Team for them to be aware of your request.
If you would like to add anything here, please post your ideas and feedback or submit a ticket with us.
Wojciech Nowak / Keepit Customer Service