This article says that HDR10+ support was added with os16, meaning the 2nd gen ATV4k should run it. So what actually changed in this latest gen besides the usbc remote and the enet hub option??

Apple TV now support Samsung’s HDR10+ video standard
HDR10+ video standard, which competes with Dolby Vision and is co-developed by Samsung, is now supported on the Apple TV with the tvOS 16 update.
www.sammobile.com