I think it probably is his last race, despite what he is saying in interviews. I like Checo, and overall he has been a good number 2 driver for Red Bull. But he is in a slump this year, not sure why, but it happens to all drivers at some point. Unfortunately for him he is in a completely ruthless team and he will likely be out next year.
Maybe Red Bull will see if can reset over the winter break and give him another chance, but it's not looking likely judging by the rumours in the press.