Hola Georgina
If the HOA foreclosure properly named and served the reverse mortgage lender and they did not respond or pay the HOA debt, then in most cases that mortgage is wiped out by the foreclosure. A reverse mortgage is still a mortgage, and notice is what matters, not whether they chose to participate.
The real risk is not the reverse mortgage itself but whether service was done correctly and the final judgment clearly terminated their interest. If service or notice was defective, the lender may try to come back later and challenge the foreclosure.
Disclaimer: This is not legal advice, just an opinion based on experience, and consulting local counsel is always recommended.
With the case number, go to the county’s civil court docket and open the foreclosure case. There you can review the summons and service returns to see if the reverse mortgage lender was properly named, served, and when service was completed. That record is what confirms whether service was done correctly.