Hello:
No, each game (most of them in any case) has its own set of forums.
In the case of Diablo IV, you will find them here: https://eu.forums.blizzard.com/en/d4/
You can provide game feedback in one of the General Discussion forums (PC or Console as the case may be).
The Diablo IV forums are available in several languages; you will find a complete list in this Support article: https://eu.support.blizzard.com/en/article/333763 (copy URL in your browser).
Best of luck in your games !