It feels like one of those things where the context of the meeting/call should be taken in: was the scheduled time of this call for an hour and you've left 10 minutes in, maybe a confirmation dialog is more useful than when you've decided to leave within a few minutes of the finish time. Doesn't cover all the edge cases etc., but just observing that "the right UX" is super contextual and not a one size fits all thing.
Whether taking that context into account is a good idea is very debateable.
The more contextually 'intelligent' a system is, the harder it is for the user to model it, and ease of user modelling is often more important than reducing the number of interactions need to complete a task.
In this particular case, it wouldn't be possible to know if your keyboard sequence that quits a call would feature an unnecessary enter at the end or not.
