Yes, owners can cancel their offer anytime up until the tenancy agreement is signed. Once the agreement is signed, it is legally binding. Most commonly, you may cancel your offer if you changed your mind right after sending it or if it was an accident.
However, we discourage owners from cancelling after both parties have accepted an offer and moved forward in the process. Renting can be very stressful and time-consuming, as you know. That's why we expect our community to respect one another's time and follow through on their promises. It's not the end of the world if you do have to cancel an offer, however it's best to avoid getting in that situation in the first place. When accepting an offer, please carefully consider what it entails and prepare to commit to the tenancy. You wouldn't like it if a tenant backed out in the middle of the offer process on you, so we simply ask for the same in return.