That power Zero possesses was responsible for the Thirteenth becoming the Void in the first place (the Memoria crystals are actually black auracite) so I doubt very much it would ever be made available to players (by all intents and purposes, it's regarded as an abomination). Zero herself is also still a Voidsent despite Hydaelyn's crystal restoring her physical form to her original mortal appearence and so she's merely continuing what she's always done.

Transformation classes always have a tendency towards causing tall poppy syndrome towards other classes alas, so like new pet classes, I doubt we'll get a transformation class other than what RPR can already do.