On the bright side, it never changes overnight so anyone letting under a license arrangement would have plenty of time to terminate in advance of an unfavourable amendment to legislation. Provided of course they keep a watch on legislative developments.
Read this question on another forum recently. It's a rented house where people come and go regularly. The original tenants are all long gone and the licensees now living there never signed a lease and do not want to become tenants. The landlord was unaware that the original tenants had moved out as they gave no notice, they just found licensees who paid deposits and then they left. Now there are four licensees in the house. If the licensees don't want to become tenants, is the landlord legally obliged to force them to sign a lease or else give them notice?