This is a great suggestion, but not sure when we'd be able to get to it, as we have a lot of other things on our (internal) roadmap.

However, you can already have a workaround where you cancel the bad meeting, and re-book-it for the customer (with the same details they provided) at the same time but with the correct email.

Hope this helps.

Of course I did this workaround. But would be nice to have it. Don't hurry. My other suggestions and wishes for improvement are way more important. ;-)