I don't think it's illegal to question events anywhere. I don't think anyone has been put in jail or fined for genuinely wondering about the historical facts whether the mainstream story is correct .declarative 'truth' type statements like the ones made above by mrolonzo are a different storyAre there other historic events that are illegal to question in some countries?
but if this is what you mean, yeah this applies to other events https://en.wikipedia.org/wiki/Legality_of_Holocaust_denial#Poland
as you can see here in Poland, Lithuania, Czech republic, Slovakia, Hungary denying communist/USSR crimes is against the law. and more broadly in many places denying any genocide is illegal