There's no guarantee they will ever release a new tablet, as they seem more focused on the Chromebook OS now for larger devices.
I'm fairly happy with the Pixel C, although having picked up a Pixel 2 XL phone, the phone is clearly faster and has had more attention lavished on it. The Pixel C is a nice enough little machine but I defo wouldn't pay more than the £300 it was on offer for. It's a lot laggier than the Pixel 2 phone and the software isn't as developed.
Keep an eye on the second hand market though. Or maybe consider the Galaxy Tab S3 or whatever its called. Or if you have a large budget, maybe consider a Win10 hybrid and running an android emulator (or find a way of doing what you need in windows).