If by emulation you mean your ability to emulate, absolutely not. Its a portable program, you can find countless mirrors of the downloads or ask someone you know and trust for a copy. If you mean active development in 3DS emulation... Yeah probably dead.

Not like there will be new games. So at least compatibility is not an issue.
As for efficiency: We'll see what other devs will do.

Citra seemed like a finished product and the code is open source, I don't see why anyone couldn't just pick it up again start development again as long as it isn't the main team.