So, as everyone knows, Mewtwo has a new forme. But do you think this was a good idea?
I personally think not, for two reasons:
Firstly, I have grown sick of Game Freak giving every single new legendary Pokémon multiple formes, and going as far as to give old Pokémon new forms (which I see as treading on sacred ground, especially Mewtwo) just makes things worse.
Secondly, changing a classic, an icon that makes Pokémon as well-known as it is, is suicide IMO. If they gave Pikachu a second forme, imagine the backlash they'd get then! Mewtwo is no different. Changing the Mewtwo everyone knows and loves by giving it a new forme is also going to cause massive fan backlash, from present and past fans alike.