Sorry it's an old thread, but I just finally got a 3D capable projector and PS4 to play the discs....
IMO, this should not be legal to restrict the disc like that artificially given the claims they made early on that 3D discs would play on a 2D player. Most include a 2D disc, but some don't (e.g. Oz The Great And Powerful is a 3D Blu-Ray Player ONLY title that doesn't include a 2D disc, just a digital copy). But then neither should it be legal to disable the skip buttons and force advertising on you after you've purchased a movie; who the heck should have to put up with 10 year old ads thrown in your face in the future (sadly the PS4 *BEGS* you every single time you start a BD to turn BD Live back on so they can spam you with Internet movie previews).
Fortunately, no amount of ads or flags stops one from ripping the 3D disc and playing the resultant file in a player like Kodi in 2D and skipping all the freaking previews and annoying menus, etc. (still can't do it with 4K so screw the Ultra discs). Still, no wonder 3D Blu-Ray is dying. 3D BD was marketed as being fully backwards compatible with 2D players when it came out. They should have said, "Unless we don't feel like it, which is most of the time."
Sony has gone to even lower depths lately. They stopped putting Atmos meta code on the 2D and/or 3D discs included even though it's fully compatible with both (e.g. Ghostbusters Ultra 4K + 3D + 2D + Digital only has Atmos on the 4K disc...as if I don't want height information when I watch it in 3D!?!?!?!? WTF!?!? I mean it's one thing if they were only doing that for 4K discs by themselves (which I don't think exist; they all pack a 1080p disc too) as that's Sony's way to "encouraging" you to only buy more expensive (and therefore more profitable) 4K discs even if you don't have a 4K set (e.g. my new Epson 3100 projector is only 1080p since only Sony has true 4K projectors and they still cost $5000+ with no lens shift). But then I'd need a 4K player just to down-convert to a compatible signals and here AGAIN, *SONY* (inventor of BD) doesn't include 4K support in the Playstation 4 (while oddly Microsoft does and costs $20-30 less)! But what exactly is the point of not including Atmos on the 2D or 3D discs that are included in a pack set? You already bought the 4K disc! Are they that afraid you'll sell it to someone that would otherwise buy the separate 1080p Blu-Ray that won't include Atmos? Yeah, I could see that. But how many people have Atmos receivers right now (and actually have the height speakers needed to make ANY difference what-so-ever) that they're that worried about it that they'd rather screw over the people that did buy that equipment (say a real home theater fan that wants a really big screen and therefore needs a projector...but projectors don't support 4K worth a darn yet) by giving them 5.1 only (as Ghostbusters does in both 3D and 2D) ???
You'd think they'd want to encourage 4K sales by getting as many 4K players into houses as quickly as possible (worked for regular BD with the PS3), but no...they apparently literally want Ultra 4K BD to FAIL so they can proceed with a streaming store instead....? It makes NO SENSE (yet they indicated streaming "is the future" as the reason they didn't include a 4K BD drive...Sony--maker of BD thinks streaming is the future and so there's no point in having a 4K drive on a PS4..... (FACE PALM)
I think maybe someone in Sony's Playstation division should be FIRED.