I realise that, it's purely a "this is what I would like" - I realise it would never happen and my opinions do not represent the majority of HaloGAF, let alone Halo buyers.
However, what SHOULD happen is a map import tool. There's probably some .map issues though, right? :/
Actually, I talked about a Rock Band-style map export in this thread before (well, a previous version). It's feasible to do it, with planning. Heck, the Halo 2 Map Pack disc is just installing map files to the hard drive for Halo 2 to read.
But seeing as how they won't even do the smart thing and let Reach export the maps from the disc so that Anniversary can read them (which is feasible, based off previous Halo titles, barring Reach's content bug), I don't have much hope of them even doing disc export. They could technically cheat it by just having it be a marketplace hotlink to a download pack where the maps are "rebaked" for Halo 5/6, but then you'd probably have people bitch that those maps aren't on the same graphical level as the later games.
I'm done buying remakes though. Just please.. stop. A majority of Reach's DLC content was remakes. Let's not have that happen again. Remake packs should be free from here on out. I want the money I paid for Prisoner back.