Seems like Kvyat has confirmed the test.
If RB wasn't too convinced about da Costa, this last race isn't going to help. His season hasn't been that good (sometimes because of reliability sometimes other things) and I'm not too sure about him going to TR anymore
Maybe they should let him do a couple of FP1 in the Toro Rosso in the last races to see what he can do in a F1 car.