I find this hard to believe.
The 12 month flight inspection requirements are driven by ICAO Annex 10/Doc 8071, not Airservices Australia "gold plating" the process.
By my reading the CAA in the UK does not require flight testing of NDB's. The FAA has recently announced that it will cease flight testing of NDB's.
My reading of the ICAO Annex is that for NDB's a) it doesn't specify that ALL NDB's must be subject to the review and b) its not at all clear that flight testing is required annually. It actually seems very vague on the recurrent period of flight testing (as opposed to ground monitoring).
So, yes. In my opinion, it does appear that AsA has taken a gold plating approach which has led to unnecessary ground based navaid closure that does compromise flight safety.
And for the poster that doubted GPS jamming. Here is a fresh advisory from the FAA on GPS jamming trials:
https://news.slashdot.org/story/16/0...the-west-coast