Good Morning:

I believe the question was "What forms does he file for 2020".  Since that is the question the only answer is that he will file form 1040 as that is the only form that is available for an Individual Income Tax return.  All of the other information is irrelevant to 2020 and his status would be as a single person for tax purposes unless he has other dependents.

The other issues relates only to his filing for 2019.