A link for a chat is created when a booking is made. If a booking is cancelled, it may impact the ability to chat depending on when the cancellation happened.
Chat has not started
If the guest clicks on the initial Guest Chat link in their email and the booking is cancelled, they will see an error message.
Chat has started
If the guest has already started chatting with you and the booking is then cancelled, they will continue to be able to chat with you.