Frehley said, "I'm on good terms with Paul and Gene,"
The engagement at Planet Hollywood will launch the last week of December.
Simmons credited his vaccination for keeping his infection "minimal".
The diagnosis comes less than a week after his bandmate Paul Stanley's.
The band issued a statement confirming the diagnosis after the PA venue tweeted that the show on Thursday night was being rescheduled.
Simmons implied in a recent interview that the former VH frontman was past his prime.
Roth was the opener for the February/March 2020 leg of KISS's farewell tour, but is not on the rescheduled dates.
The VAN HALEN frontman opened the first 2020 leg of the tour before it was postponed.
Snider has once again dismissed the notion that rock is dead.
The legendary rockers previously set up shop in Sin City in 2014.