I guess I can see where others are coming from (the LLM is different than a literal rubber duck) but I feel like the "can't reply" part was never more than an incidental consequence. To me the "why" of it was always that I need to solve my problem and I don't want to disturb my colleagues (or am unable to contact anyone in the first place for some reason).

So where others see "rubber ducking" as explaining to an object that is incapable of response, I've always seen it as explaining something without turning to others who are steeped in the problem. For example I would consider explaining something to a nontechnical friend to qualify as rubber ducking. The "WTF" interjections definitely make it more effective (the rubber duck consistently fails to notify me if I leave out key details).