I've seen several examples on profiles where a comment was left on a cancellation statement in the reviews.
So unless Airbnb has changed this, it is pssible to leave a short explanation. You have to make sure you are on top of this yourself to stay within the time frame because I don't assume Airbnb will send you a notification as is the case with posted reviews.
And it's always better to set up new listings and try out functions before the listing goes live.
And yes, sometimes also better to suck it up and accept the booking.