Square won't remake FF7, and even if they did, they wouldn't make it moddable.
They're too busy scaring their stockholders to death with new, untested ideas, rather than release a product that literally every square fan has been asking for for over a decade.
All that being said, Q-Gears is a big step in that direction. It's an engine rewrite that works off FF7's file formats, but since we'll have the source code, we'd be able to add lots of cool stuf to it that we currently can't via modding alone.