Peter Campbell, it's a fair question, but really what's trying to be achieved here is to allow choice for individuals or small teams the best-in-class touch and inking experience that the Hub 2s provide, but the flexibility of the Windows 10 Professional OS, so they can have their own personal experience and install Win32 32-bit or 64-bit applications that can't be installed on the Hub 2s Teams OS. Think executive offices, home offices or small teams of engineering, marketing, IT and creative employees (5 - 10 people).
Yes, you could absolutely have a wall-mounted LCD with a room PC, but what's the end-user experience going to be like with touch, inking and collaboration?
The development of the Windows 10 Teams Hub OS is ongoing and full steam ahead, as you can read at the recent Blog post yoabar posted on the 22nd of July - https://techcommunity.microsoft.com/t5/surface-it-pro-blog/new-surface-hub-os-update-released-for-public-preview/ba-p/1534823