I'm not getting into semantics. If you take physical action and stop advertising the property for rent, or make a conscious decision to not advertise at all after the last renter moves out, then it's reasonable to say that the property is no longer "held out and available" for rent.
My overall view is that if the property is sold within 5-6 months of the last tenant moving out, don't bother with all the conversion stuff and just declare it a rental for the entire time. Makes it easier and simpler to report the sale, and I've never known the IRS to question a sale where the property sat vacant for a few months prior to the sale.
I have heard of situations where the property was vacant for close to a year (or more than a year) and that would raise questions. But I personally have no experience with such a situation nor do I know anyone who did. Only what I've read from sources that I would not reference.
