Now here's the STUPIDEST COVID-19 restriction I've heard to date...

This has been a standard requirement in most counties in California long before COVID, any groomer associated with a vet will most likely require the shots be up to date, you may find an independent that doesn't

Same here on the East Coast. Nothing to do with the current state of affairs; the standard dogs stuff - kennel cough, Parvo, etc, can be a killer to young/small dogs.