Hello, I'm also a bit confused about these changes. I'm referring specifically to the removal of the path over Waden Hill and the path which it connects to east of the Avenue which then joins to the path north of the A4.
Firstly, the paths are still being mown - from what I can tell they have been mown within the last week or two. 
Secondly, both of them appear to have minimal wear and it's hard to imagine that any damage is being caused by walkers using them, especially in terms of archaeological damage. 
Regardless, if the paths are to be closed (which would be a shame) they should be removed from OSM, from the NT website and notices should be erected at the path entrance points or they should be physically closed off. OSM needs to reflect what the real-world situation is and shouldn't be used try and manipulate people's movements. 