Need help determining if my nephew will still be eligible for CSPA

[Seriousjokerwhyso]

My sister had visa interview scheduled in 1st week of April 2020 but due to Covid-19 it was cancelled.
My nephew is eligible for CSPA and was of 20years 9 months when the PD became current in April.His name was not there in Ceac website and we decided to inform consulate after we get the visa interview date but the interview got cancelled and we didn't got reply of Covid-19 alert when we emailed consulate for adding his name to join the interview.
Also now they have suspended services for next two months.
So Now when the next interview will be scheduled and if it is scheduled after 1st week of july, 2020...He will turn of age 21 years according to immigration laws(i.e even after applying CSPA) . So I need opinion if he will still be considered eligible for getting visa based on CSPA .?? Because the PD got current in April when he was still not 21 years of age.
Thanks for helping!

[newacct]

His CSPA age is determined at the time a visa number became available for him. A delay in the interview and visa issuance should not affect his CSPA age unless the dates on the visa bulletin retrogress to the point where a visa number is no longer available for them.