Is this enforceable on Airbnb? If a guest doesn’t want to provide names, I know that Airbnb won’t make them. A host could still cancel a reservation before it starts if a guest doesn’t provide the names, but that’s a slippery slope with Airbnb’s history of penalizing hosts for cancellations.
Again, how can you enforce this? As a host, you can’t just cancel without the guest getting a refund and there is no evidence I’ve ever read that says Airbnb will do it for you without refunding the guest.
Putting this kind of wording in your listing and house rules probably will help. However, if you still get a guest that tries to sneak in extra people, don’t count on Airbnb backing you up on your rules or not penalizing you for enforcing them.