SBS2011 to WS2016 migrating covers migration of mapped drives. It looks that it is just rights migration, what about moving files from SBS2100 users shared folders to WS2016 shared folders? Should it be done manually?
In chapter 12 we explain how to migrate any shares you have and we explain how to use robocopy to copy the files + security. In chapter 13 we explain how to change the Group Policy for redirected folders so that it is pointing to the new server. If you do that and follow the steps in chapter 13 the files will be moved automatically once a user gets the new policy applied. You must make sure that this gets applied on ALL workstations in our Lan.