I thought she did a fantastic job to be honest. They'd have had their O2 masks on, a TON of distraction going on in the cockpit, and meanwhile they need to (and did a great job of) stay focused on flying the airplane. An airplane that I'm sure was not an easy one to fly in that "configuration" -- not only did they lose pressure and an engine, but they also knew that they had damage to the aircraft structure, which they undoubtedly felt in the controls. Meanwhile, the engine was not only lost but also appears to be in such a state where it's going to be creating a very substantial amount of additional drag on the aircraft in a way that is just very far from normal.
I think a request for no more frequency changes is not asking for very much, and I think it makes total sense given the situation -- the crew wants to focus on their #1 priority, flying the aircraft, and I think that anything they can do to quickly & safely reduce crew workload in that situation is a very good thing to request.
Frankly I think the crew did a very good job given the situation, if anything I thought ATC comms were maybe a bit verbose but generally I think all parties did a good job from what little we know at this juncture. Hats off to the crew in my opinion for what was, by all accounts thus far, a textbook handling of a pretty ugly situation to find oneself in.