So here is my problem with that.
Several of my favorite types of sorcerer don't "transform" into anything. They just have magic that's themed to a certain type of spellcasting. shadow magic doesn't turn you into an undead creature, but it does allow you to tap into magic of the night and gloom. Lunar sorcery is about the moon powering your spells, not turning you into anything. I don't want to lose the option to have sorcerers who are just "storm magic" or "wild magic" without turning into an elemental or a slaad. And I don't want to get saddled with a spell book by being a wizard.
The D&D Next dragon sorcerer was a neat idea for a dragon disciple gish monster class, but it would have been limited to "this subclass turns you into a different monster" and always stuck in the "start a caster, end a melee monster" model. The sorcerer chassis could be used for so many cool ideas for thematic magic (non-aberrant psionics, time magic, elementalists, FF summoners with pets, etc) but everyone, WotC included, gets stuck in the "this turns you into a clockwork monster!" style of thinking.