I think a tool with this kind of UX is the future of engineering orgs. It reminds me a lot of JetBrains Space (which I already thought was a good idea back then), but with agents.

I don't see a lot of information about the Git hosting aspect of the product on the website, though. Somewhat doubtful that they will be able to make a Git forge with similar polish to GitLab

It subjectively seems to me that integrating with an existing forge (e.g. Forgejo) on the API layer and rebuilding the auth and frontend is a better bet. You get stable features like PRs, permissions and CI actions out of the box and they stay synced with known formats in the community and so make your tool easy to adopt. Though making a forge from scratch does have advantages especially for internal company use cases.

Another problem I see with Buzz is that the tool doesn't seem to be taking advantage of its vertical integration inside its UX enough. There is a lot more you can do with full control over Git hosting, project context, and org-wide chat in a single tool than what this tool attempts to do right now.