a lot are OOP, just not OOS as you can still find some in some stores. You can find most the old WB ones still in Barnes and Noble tho at high prices (34.99)
But it has pretty much become routine now that when they make a digibook (WB) that its for the first pressing ... so when stock is gone, its gone. Then only amaray plastic version is available.
If you see a digibook in store, and you see a plastic version next to it. That means its OOP just not OOS. Now they are releasing these on the same day too. (for many titles) like with Outlaw Josey Wales for instance, plastic version and book version still out there and released on same day. When they need to order more stock again it wont be the more costlier digibook version.
Shawshank, Green Mile and others are a little more harder to come by these days. Tho not impossible to find by any means.
The more rare ones are the Sony Pictures ones.
Silverado, A River Run Through It etc