what are the chances that we'll get a new eeveelution in ORAS?

I know it seems unlikely but think about it this way, every gen that intruded eeveelutions did it in sets of two. This means gen 6 is still missing one.

Eevee's are major selling points, adding a new one for ORAS will help spread hype

This also wouldn't be the first time a new pokemon was introduced in a remake, deoxys being in FRLG shows it can happen.