The Creation engine does seem more optimized than the Gamebryo engine. But if moving to the Cration engine meant removing Attributes I would have to say no.
Not an engine. Gamebryo is a renderer.
Creation Engine has existed since Morrowind, Skyrim just made it official. NetImmerse (later Gamebryo) was simply the middleware licensed for the engine's render. Granted, that's a fair bit of work, but the render is only half of the actual game engine.
Every single game Bethesda Game Studios has made was built on the same engine, tweaked and optimized and upgraded from before. Skyrim is no exception.
Considering the Oblivion remake, I would say no because there really isn't much to gain by moving to a new version of Creation Engine if the game and its base data remains unchanged. When Bethesda actually changes the render entirely, or if we get an upgraded data master that allows for much more to be done with it,
then I'll think about it.