There's no incentive to keep a game alive after the server costs outlive the monthly income generated. Only a handful of games have been kept alive out of pure preservation or low cost (or in some cases, because the publishers just forgot about it).
Regulation might be necessary since in the last 8 years of gaming, less and less games have been able to be preserved. And we had had outrageous examples like, The Crew, where fans have been able to reverse engineer an analogue to Ubisoft's servers in less than a year. Ubisoft have no incentive, so maybe it is time they are forced to.