From Bulbapedia, the community-driven Pokémon encyclopedia.
:1. I would say no. Proximity usually doesn't mean a thing when it comes to things like this. Regardless of that, it's a fantasy. For all we know these Pokémon aren't even real but just a representation of the Cerulean Gym.
:2. Obviously, yes. We know completely nothing about M22 Mewtwo, whether it's the same one as M01 Mewtwo or not. <span style="font-family:Arial Black"><span style="color:Red">☼ Blazing</span>[[User talk:Blazingfist|<span style="color:red">Fist ☼</span>]]</span> 13:13, 23 December 2018 (UTC)