Perhaps what he means is that everyone is well within their rights to make their own backup copy of anything they bought - You can buy a DVD and make a copy, in case the original gets scratched or broken. That’s “fair use”. However, any kind of public distribution of that fair use copy is 100% breach of copyright. That’s not a grey area.
Copying prints should be the same way, since prints can also get scratched, colors can fade, or it can develop Vinegar Syndrome and become unusable, so making a digital backup so that you can continue to enjoy the film even if it gets chewed up in a projector, would be fair use, again, so long as it’s not publicly distributed.
However, unlike a DVD, which was licensed by a distributer and legally purchased from a retail outlet, 35mm prints were never supposed to be in our hands. The studios expected them all to either be returned or destroyed at the end of their theatrical run. Unless the studio (or the cinema) threw them in the trash and put them at the curb for pickup, in which case they are once again fair game. I’m not a lawyer, so I don’t know exactly how it would play in a court of law, but the FBI Warning at the start of every DVD and Bluray doesn’t mention “Fair Use” as an option, and makes it crystal clear that distribution, even without financial profit is very much against the law.
If I were a moderator on Reddit, I would want to remove all the links simply because by leaving them up, Reddit is clearly allowing the illegal distribution of copyrighted works, and it would be Reddit that receives the first DCMA takedown notices and cease and desist letters from concerned studio lawyers, not the people posting them, who are largely anonymous. You’ll notice that although we discuss all these projects here on OT, you won’t find a single publicly posted link to download any copyrighted works.