In the Protime tenant I have an MS Visio or MS Project licence. Can I keep it?

Yes. If you had an MS Visio or MS Project license, you will have a license after the migration too.

But! The license is only valid for 2 months. If you still need it (after 2 months) you will need to do a new request. If validated, the license will be valid for a new period of 2 months.