We know Canon will release new lenses for the EOS M system in 2017. Rumor had it, there will be at least one prime lens to come (though two are rumored, a 35mm and a 50mm).
I got word (thanks) that Canon may announce an 18-135mm IS STM lens of “higher quality” than the available EF-M lenses. I interpret “higher quality” as referring to a lens with better optics and a constant and possibly fast aperture. Unfortunately, I have not received any specification for such a lens, and I didn’t spot any patent for an EF-M 18-135mm IS STM lens so far.
There is only one thing you can be sure about: there will be new lenses for the EOS M system in 2017, we just have no idea what lenses to expect.