What is the purpose of this forum?

Yep, it's intended for class feedback, and for us to share and discuss upcoming changes with you as well. In Legion, there's a lot we're able to do with class development that doesn't require a major patch - hence "Class Development" and not "7.2 PTR Class Development" as the name.

The individual class forums can be a good place for feedback, but also serve as a great place for players to discuss their class with each other: sharing builds, rotations, stat preferences, etc. We're trying this forum out as a bit of an experiment to see how well separating those two types of discussions can work.