Requested Titles listed but not available for purchase

[Thecatdemon]

I hope this is posted in the right spot. I can delete and repost in a more appropriate part of the forum if needed.

I have noticed that a few titles that I have requested in the past have been added, (complete with cast, ratings, tomatometer, and even trailers some times) but are unavailable for purchase, renting, or even streaming with ads. Some examples: The Call of Cthulhu, Fateful Findings, Happiness, Session 9, Behind The Mask: The Rise of Leslie Vernon. I'd be happy to provide a more complete list if it would help. I've been impressed with how often things I've requested are added. (They just usually aren't available yet.)

Constantine: City of Demons is another film that you are unable to purchase directly on VUDU (though you can purchase that particular film through another service hooked up with Movies Anywhere, and then stream it through VUDU.)

I've also seen titles on here before that you can rent but not purchase as well, such as Mulholland Drive and Terminator 2: Judgement Day (Director's Cut). I feel like that's intentional, probably some studio agreement or something. But if it's not, that'd be cool to look into as well.

Just thought I'd ask if all that is normal, if there's a general timeframe before certain titles might be available for purchase, and what causes all of that. If it is just studio stuff, I guess that makes sense, but I don't understand why a new title would be listed if it still won't be available months later. I've requested other titles that became available seemingly immediately after they were added, like Perfect Blue.

[Wasteland]

I'm able to purchase Constantine: City of Demons on Vudu...