In principle, understanding when it is appropriate to interrupt is the same sort of problem as understanding when it is appropriate to use a specific tool or AP

In principle, understanding when it is appropriate to interrupt is the same sort of problem as understanding when it is appropriate to use a specific tool or API call. Both are deviations from natural language that the model has to decide to employ based on the context of the input, so yes it should be very possible for LLMs to do it. You're asking if they would do it well or if they would instead get it completely wrong and interrupt you all the time with irrelevant nonsense - I'm going to say that depends entirely on implementation. The bigger issue, in my opinion, is that current models running on current hardware at reasonable costs simply aren't performant enough to do the faster-than-speech prediction that is required to execute the concept well.