First off, let's take https://www.reddit.com/r/FFXIVhousingmarket/ into consideration. We're less than a week after the expansion, and on that page are (at the time of writing) properties in Shirogane up for sale. That's housing that are denied people who will love and use their new property because of greed alone.

House flipping needs to die.

Which is exactly why SE needs to add an invisible random timer when a property is released that puts the property into a limbo state (where no one can own it, and no one can use it) that lasts between one to twenty four hours. The only thing the players should see on the timer is that it exists, and the players should NEVER be able to see how much time is remaining on the timer.

That change would outright kill the house flipping market - which should never have been a thing to begin with.