Certainly ain't like the good old days!!
Indeed; if thinks don't change they stay the same. Trouble is the change should be an improvement, but sadly.................
Regarding the A/T in ARM. I seem to remember this was the case on B757/767. I think those with experience of this possibility investigated/experimented and discovered it was possible on B737's. Every B737 operator I flew with, CL & NG, banned it. I see Boeing uses the phrase "not recommend". I remember an old SOP manual of mine which had a list of definitions: e.g. should not = must not = forbidden". "not recommended" = is not the normal method but is not forbidden.
So what does Boeing really mean? Denti tells us that Boeing 'approved' its use in his airline. Presumably that was at customer's request. That would suggest it is not forbidden.
In my B737CL days an RA was disconnect A/P and follow avoidance guidance. Then came NG and it's SOP, which then filtered down to CL models, was to also disconnect A/T. The reason being was to comply with the philosophy of All ON or All OFF. It was not a technical necessity, yet the 'experts at Boeing' decided it was better: not from an airmanship or technical point of view, but from a pedantic philosophy point of view. It has been discussed previously and some have said there are gotchas if you leave it in. I've also seen, in the sim, many serious gotchas after it was disconnected. Personally I preferred the earlier method. Disconnecting A/T is recommended and thus became an SOP; but it does help to understand the why's & wherefore's. But as has been mentioned elsewhere we are treated too often and too much as naughty children who should do only as we are told and not to question. However, when needs must we are supposed to act using the best solution for the unexpected scenario; except that ono-one had written that one down yet.
Agh!