Will Lego release new Toa?
If you're referring to wave 1 of Bionicle 2015 then no but any other waves are yet to be known. ~Detox
More than likely there will be new characters that are Toa wether it's a reboot or not, but if they'll be released as sets, we'll have to wait and see.
I think they'll stick with Tahu and his team for the time being.
I agree. Remember that the original Mata (and later Nuva) actually received four years total of spotlight (the Mata in 01, the Nuva at the end of 02, the Nuva retaining the spotlight with the advent of Takanuva in 03, and the Phantoka/Mistika arc throughout 08). I see no reason for the Mata to not continue receiving attention through the third year of G2. After 2017, however, I would love to see new Toa. Either new faces and personalities entirely, or (my personal preference) a reboot of the Toa Inika. Not a Mahri reboot where everyone looks part fish. An Inika reboot, with Matoro.
The Inika fanboy inside me would no doubt die of hype to see Jaller, Matoro and the rest re-immortalized in G2 Bionicle.
The thing that I think of more is will they make the rest of the elements? like light, gravity, plazma and ofcourse air?
I think the current Toa will go the Hero Factory route and stick around for a few more years with them getting upgrades every so often.