I just learned today that some of will be happy, the staff is working on such a timer ( I was not aware before). They have decided 4 days, so if a guest has not finalized After 4 days,the preapproval will be cancelled automatically.
It should be released on the site in a few weeks, before the end of 2024 if everything is ok with the tests.
I am glad they are working on a timer where the exchange is canceled, not sure if 4 days is long enough given time differences and such. I will say we have had a host cancel our pre-approval like the day before we were finalizing. We let it go a few days to make sure our travel partners were good with it and the host got another request. We contacted them right away and did salvage the exchange but I can see how someone might not want to wait. I do wish there was a discussion step before preapproval written into the system as we always discuss and agree on times and such.