There are a few new rules regarding towns, which you can find here. Please note that these are not actually new rules, per se, but have just been added to the wiki. These rules are Section VII, clauses IV and V, and Clause III has also been changed.
You need to define the legitimate reasons required for an original owner to repo a sold town. I could sell a town and demand it back just because I want it back and there would be absolutely nothing illegitimate about that.
