Saw this mention on another website and thought I'd pass it along....
The museum's latest calendar indicates that they'll be open into the evenings on BOTH Fridays and Saturdays from April 22 through the end of October. It also looks like they're bringing back free-last-Sundays-of-the-month starting at the end of this month through the rest of the year. This is, BTW, NOT a day I'd recommend going anywhere near the place. There are some other random closure days and still others with altered hours noted. The calendar is here:
https://m.museivaticani.va/content/dam/museivaticani/pdf/utilities/calendario_musei.pdf
"D" is Sunday (Domenica) "V" and "S" are Friday (Venerdi) and Saturday (Sabato) respectively. The calendar reads vertically versus the usual horizontal format.