I don't feel like this is a good way to handle inactive FC housing.
If their intention was to solely free up room for more active FC, then it should try to promote the trade and bidding of land exchange.

I don't think evicting an inactive FC house would give an equal chance an active FC of obtaining a house. But instead turns into a 'first come first serve' basis, like the initial launch of housing.
You might instead have devoted people just loitering outside of an FC house looking at the time tick down. Is that what you really want, to further edge out the casual FCs for equal opportunity housing?

As for the end user who owns a FC house, being forcefully evicted is akin to removal of inactive player accounts.
No one want to lose things they have spent time and effort on obtaining. Regardless if they are actively using it or not.
They want to know when they return to a game, that their belongings are still there, and not completely robbed from them.

Either way, FC housing activities at the moment is still rather bare.
At best there are a few crafters there that runs between the house and near by market boards, with an occasional person tending the gardens.
At worst, people just AFK pose/dance there when there is nothing else to do.