Do you delete data from the source platform?
No, the Migration Wizard does not delete any data from the source platform because the service itself cannot modify the data. First, we read the source database, then make a copy of the records and finally import the copy to the target platform. That’s it.
No records in the source platform are deleted or changed during and after the migration. So you have nothing to worry about as you will be able to access the data on your old platform any time you want.