This isn’t going to be possible, primarily because for anything in your code to execute it needs to be activated, but if you’re deleting a plugin it has already been deactivated.
You can’t ask on deactivation because there are a lot of cases were the plugin may be automatically deactivated, e.g. updates
Most of the scenarios where you would have those hooks such as register_uninstall_hook etc would not occur on an admin page but inside an iframe.
To be able to do this, you would need the following:
- A second plugin to watch for the first plugins deactivation
- Javascript to watch for the deletion/uninstall links being clicked
This will fail if:
- The second plugin isn’t installed ( people probably won’t bother installing it if the only purpose is to provide you with feedback )
- The first plugin is removed from the filesystem rather than the GUI
- The second plugin is deactivated
Also consider what happens when the plugin is ran on a multisite and network activated/deactivated
My recommendation would be to not bother. Aside from the technical issues implementing it, it’s bad user experience, and I can’t see how it would do anything other than annoy your end users ( encouraging them to never install the plugin again )