Fair enough...assuming that there is no reason to assume that ATOS are being obstructive when it comes to providing authorised recordings.
But...
Note the sly elision of making recordings into "intimidate staff" or "publish[ing] online" information. There are many reasons why a recording might be made, and my suspicion is that intimidation or "publishing online" are the tiniest of minorities of uses to which they could be put. And, in any case, I imagine that that kind of behaviour is more than adequately covered by other forms of legislation.
It also begs the question as to why ATOS might be assuming that people would respond so negatively to them - have they accidentally betrayed themselves in their acknowledgement that what they are doing is so unpopular?
I think the vague non-threat of "appropriate action" is interesting - I imagine that, in law, there would be precious little they could do about "unauthorised recordings", so they are forced to resort to generalised - and, I imagine, legally meaningless - threats. The worst of which is that they will report the infraction to the DWP who will, presumably, do what the DWP always does and terminate someone's benefits.
Nice bit of plausible deniability - "any lies we tell or misrepresentations we make are part of DWP policy - take it up with them". While, of course, the DWP is busy saying "we do not conduct the assessments, we only make decisions on the basis of their recommendations". Where's the accountability?