We have two examples of “official history’ in the news lately, the Turkish official history that there was no Armenian massacre and the French official history that there was an Armenian massacre. In both cases you can get fined and possibly go to jail for not following that official history. So you are banned from making alternate history in Turkey or France about an Armenian massacre.
I don't know the details of either French or Turkish law here, but I'd imagine AH, if presented as AH, is exempt precisely because by definition that is saying "this did not happen".
Even if, eg, a Turkish prosecution were sought on an AH with no Armenian massacre (because that would be saying there
was such a massacre in RL) then the author may claim their POD as defence, so long as "no massacre" isn't the POD itself.
Where does the dividing point lie between Alternate History and Revisionist History, I wonder?
Come to that, the division between AH as a specific form and all fiction: Even contemporary fiction like soap operas are set in the past (albeit very recent) and concern characters who do not exist in events which did not happen.