Who knows? I certainly wouldn't let that deter though. Cancel them and open up your calendar. I've cancelled only a couple travelers EVER, and one was because the guest told me he and his buddies were grad students taking a break from studies. Turns out he was a sophomore on the hockey team (those pesky sports bios!) I cancelled him and got on with my life.
I won't ever let metrics hold my property hostage.
IMO, jumping straight to canceling on a guest without first requesting them to withdraw the request or initiate a cancel feels a bit of a rash course of action. Unless you know that taking a hit to your metrics won't impact your ranking, I would recommend giving the guest at least a couple of hours to take action first. I would rather have my calendar be "held hostage" a few hours (or 24 for that matter) if it means I won't have a blow to my metrics that would haunt me for a year.
You said you have a "reservation request" so you must be on 24-decision. Did you accept the booking? If not, tell the traveler that you cannot accommodate their booking request and that they need withdraw the request within 24 hours of the time they submitted the request. Send them this link: https://help.vrbo.com/articles/How-do-I-withdraw-my-pending-booking-request
If you accepted, then persuade the guest to submit a cancellation immediately so that their card will be credited back. Telling the guest that their intended use of your property is a violation of your house rules and that you won't provide them access to your property is usually enough persuasion.
I'm on 24-decision (not Instant Book) because it's a purely hassle-free way to vet a traveler. Since the advent of the withdraw feature, I've persuaded two travelers to withdraw after learning of planned parties and over-occupancy (both serious events that would cause me to lose my VR license). Just had one a few days ago for a planned party and they withdrew the request. For me, the Withdraw Request has been the best feature that Vrbo introduced because no money ever changes hands. The transaction is literally voided and it's like the booking request never happened.
Thanks for the reply and the link.
I get quite a few booking requests with question regarding suitability of my property. In this case, they wanted to know if they could keep a dog outside on my property. I did not approve the request, clicked on the "reply" option and told them that a dog on my property was not allowed.
No reservation was made, but my 24 hour "penalty clock" was counting down. If I denied the request, my metrics get penalized; if the 24 hour "penalty clock" expires, my metrics get penalized. I sent them the link that you provided and they withdrew their booking request before the penalty clock expired. Thank you very much.
If not too much time has passed since they made the reservation, I'd let them cancel for free if they really felt like they wanted to bring their dog. Otherwise, trying to cancel them, you'll get dinged because you're jumping to the conclusion that they will indeed bring their dog and violate your rules. Until they bring the dog, they're not violating your rules or your rental agreement.