May be because "change this" is vague and more of a broad function and may need more clarifications. Users may have more clearer commands, like "cancel this", "I don't like this, provide an alternative" or "can you go back one step?" etc. User can just speak those requests out loud since device is listening.

Absolutely and that will be a major usability problem when LLMs get things wrong as they so often do

At one point he asked for a more relaxed version of the initial vacation plans.