Li Shenron
Legend
I think it's important to take note of what they now call metamagic is: "the ability to alter the way a spell works on the fly". In other words, they have taken the metamagic of 3e and used it in another meaning.
Exactly! In the original 3.0 view, Wizards' metamagic was always supposed to go through preparation. It represented the "scientific" approach of Wizards to spells: study and analyze spells and design variations, not improvising them. Sorcerers would apply metamagic on the fly, representing their wild and innate approach to spellcasting, like an "artist" improvising.
Only later on, by gamers' demand, designers were forced to come up with X/day on-the-fly metamagic. Conceptually IMHO a very bad move which blurred the Wizard-Sorcerer boundary even more, removing one big reason to play a Sorcerer, but 3e Sorcerers had already been treated as less important for the game since the 3.5 update which boosted everyone except them.