I noticed Type F and "Older" Fluids (ATF+4 is one of them) getting scarce a few years before corona virus came into play.
Wally world and anyone with discount prices made more room for air fresheners and cleaners and less room for oils & service supplies. They pretty much stocked just the fast sales/newer car stuff and dropped everything else.
NAPA still has everything I needed in stock or later that day. Just a week ago I bought a quart of ATF+4 which was in stock at NAPA.