Although the article is pure speculation, Motor1 has a short write up
about the possibilities of an RX-9 in the near future. This is all based off of an RX-8 being spied running the Nurburgring last year.
You do have to admit, the exterior render is nicely done. However, I don't think it will happen for a few reasons:
1) Mazda's priority is with the SkyActiv-X engine line.
2) They also have their hands full with the new Alabama plant that will be online by 2021
3) MX-5 sales are pretty low and I doubt Mazda will cannibalize them by releasing another RX coupe.
One can dream, though.