Prepping bathroom floor

[Mikeathome]

I removed small ceramic tiles from floor but the paper backing and a very thin layer of thinset remains. Can I remove the loose pieces of paper then seal the floor with a primer/sealer before laying new 12x24 tiles? The plywood backer is intact and the surface, as it stands now is level and smooth. The depth of the thinset that remains is about half the thickness of a dime.