Of course, but is there any actual evidence that these accounts are NSA related? Or is it an assumption because they are supporting the proposal (which would be very circular logic)

There's a history and a 'pattern or practice' of behavior between NSA (sometimes using other TLAs or plausibly deniable intermediaries) and standards bodies and regulatory agencies.

Demonstrating a 'pattern or practice' is the legal standard one has to meet to bust qualified immunity and shift the burden of doubt on to authorities, so I'd say it goes a fair amount past 'reasonable suspicion', which in a court is itself enough to issue search warrants.