This is awesome, excited to use this in our next migration.
After testing this out in the migration manager, I would like to retract my previous comment. This feature is half-baked: Migrating a form works fine, but the when the sheet data is migrated over, the migration manager creates two .xlsx files from the original one. The first is stored in the user's OneDrive Documents and only contains the response selections without metadata (time, responder email, etc.), the second is stored in a new subfolder called "Migrated Forms Responses from Google", it does contain metadata and appears at first to be connected to the Form.
When you view the form responses in MS Forms, the form lists 0 responses (even if there were responses migrated to the xslx docs). There's a button "Open migrated results in Excel" which when clicked opens the second xlsx doc with the migrated results. That's good, but when new responses are collected on the migrated form a THIRD xlsx doc is created in the user's OneDrive to track all new responses and the "Open migrated results in Excel" button disappears, being replaced by a link to the third xslx doc.
You can copy/paste the responses from the second xslx doc to the third, and the form continues to work, but the MS Form responses page does not update with the copied information.
Additionally, every xslx doc in the "Migrated Forms Responses from Google" says it was created by someone named "Yanan Shi" who I assume is the engineer who coded this solution and the name of the account in the backend that actually performs the migration of forms data.
I don't usually complain about Microsoft's quirky solutions as long as they are easy to communicate to users. I have no idea how I'm going to explain this "functionality" to 200 different users across the company migrating from Google drive. I appreciate that Microsoft takes the time to create solutions like this which do not directly generate revenue, and the Migration Manager has been a game changer for us as our company evolves, but I won't become complacent to companies releasing features that barely work.
tl;dr Good luck if you use this, test it thoroughly and have a plan. Hope it's fixed soon.