Since you deny a weird context switch for your eyes, are these actually inline elements? That would imply the size of the containers is changing. Which would surely be a weird context switch. But at least I can have no doubt what my action is about to affect - I get frustrated on sites when it says "you're about to delete these items" and i have no idea whether it agrees with me about which items I'm about to delete or not.

But if they're overlaid elements, like a context sensitive menu that contains two options - delete, cancel - is there any substantive difference between a menu and a modal? The main advantage of a classic menu over a modal seems to be that it has a implicit cancel option that is uniformally implemented. But nowadays, menus are implemented without toolkit support - yay dom, yay - so even that is not consistent.