Yep, you read the document correctly. It’s an improvement from when the WiFi6 access points first came out, they could only be in a wireless network with other WiFi6 access points if you wanted to use NBAR.
I imagine that eventually we’ll see greater integration, but probably not until the MX devices support NBAR too (so that they can make the combined reporting work in the Dashboard) - until then you’ll need at least two networks per site if you’re using an MX and want NBAR statistics from an MR.