That exclusive content in physical games is a cruel disservice to late discoverers. "Exclusive" content should just be delayed public release content instead - something for the early adopters, but not unavailable to people years later.
Even just the normal game, if they're discontinuing production, should be made available as a digital purchase (including STL and print-ready files) for people coming along years later. We have the technology to not screw over potential future fans, and it's not that expensive to keep a small website running - especially if they're still going as a company. Looking at you, CMON Games.