If "souls" irritates you personally, then so be it. I don't really care whether we use "souls" or "persons" However,
as you say that info is readily obtained elsewhere.
Have to take issue with that, because it's [I]not[I] always readily available. It depends on being able to get in touch with the company, on a landline or mobile phone, and they may not be able to obtain that info instantly. In the above case, as has already been said, both crew and ATC dealt professionally with the situation - ATC asked for S/POB, and did not press the crew when the answer wasn't forthcoming.