Zero percent chance it'll stay "out-of-print." I use the term loosely too, because it's so obviously a transparent marketing ploy and not a true out-of-print deal like when a company loses license rights, runs through the promised stock of a limited edition, or drops an obscure title indefinitely from its lineup due to dismal sales and general disinterest. Or if you're Paramount... who occasionally forgets they still own the rights to certain titles before falling asleep under the desk only to wake up several months later covered in old newspapers and stuff.
They're just exhausting all existing stock so when DKR is ready for release on Blu they can capitalize on its popularity and release an overpriced "complete" box set. They did the exact same thing with the Harry Potter films (but not before sending out a trillion PR releases
to all the niche outlets saying "Watch out guys, we're pulling all Harry Potter BD's from the shelves! Buy them now, buy them now! Also suck our balls thx.") I remember when the Blade Runner BD set went "OOP" a few months back
and fools started to pay outrageous prices for it. It was a fantastic way to drum up artificial demand for it and lo and behold - they're releasing it in a brand new box (hooray!) in a couple months and people who "missed them" the first time around are now champing at the bit.
By the way, you can still buy the Batman Anthology for 50 bucks from the WBShop
Anyone paying the exorbitant 3rd Party Amazon prices is an absolute ass, even the WBShop option I linked is a little too pricey in my opinion... but that's standard MSRP for this release so I guess it's not technically a rip-off. It'll certainly come back into circulation soon, and definitely by the time DKR hits BD (most likely in complete box-set form, like I said.) I also have no idea why jackasses are buying these up for around 100 bucks (or more) on eBay. If I were a scum bag I'd buy 10 of them from the WBShop and pitch them on eBay for a 400-500 profit. Some people have more dollars than sense.
When the new Superman movie comes out a year from now expect the current Blu Ray releases to go *poof
* and suddenly be worth their weight in gold on places like Amazon.... only to get re-released in a shiny new box (causing the original releases' values to fall like a stone) when the new movie readies for its BD release. That's called the Warner reach-around.