Prevent new layout styles appearing

I have created a new slide master with all the layouts that should be permitted. When I copy a slide from another presentation it brings with it a new layout style, even if I use destination theme. I know there are ways around this by then changing the layout and then removing the imported layout from the master - but this is not ideal.

Is there a way to only allow current layouts to be used? We'd like to use the new master across the company, and want to make it as automated and straightforward as possible (staff will just copy and paste and never consider the layout/slide master).