Sturdy board folders with a foam/plastic/paper hub/spider to hold disc.

This kind of packaging is quite common for CDs, especially for low quantity/self-released editions.
Not really a digipak (no plastic tray), not really a gatefold cover nor a cardboard sleeve.

It is similar to a gatefold cover, but the medium is held by a spider, often made of foam, and most have 2 or 3 panes.