I'm not sure about changing the text. That might be too attention-grabbing.
If changing the text makes the action more contextual, it tends to work well.
We applied and tested with users similar approaches [1]. some examples are the Draft namespace prototypes (where "publish draft" turns into "save" once there are changes) and the translate extension (where possible outdated translations have "Confirm translation" as the initial action and it turns into "Save" when the user modifies the translation).
A possible distraction can be produced if the change in text length has a big impact, but you can play with min-width to compensate that (giving some extra room to the button which is expected to grow). In this case, since we are talking about silent buttons, that is even less of a problem (compared to colourful primary action buttons).