As I see it, if they expanded the challenge gear to go to level 30, had an option for a universal mat to drop in typical chests (This would be a base mat that could be traded in for any of the other mats in the game) lets say, make it a UI option, and then, you could trade in for any mat you had the pack for.
I would love that, it would let me plan my gear before I got there, I could save up for say level 24 rock boots, or even level 28 cloak of flames, while not needing to do challenges if say, I did not like them, it would free up space in my inventory, it would save time for trips to the bank and any of that stuff.
Have Ebberon Epics drop a Universal Component, as opposed to Shards/Seals/Scrolls, then have it so you trade in enough of these for an Epic Upgrade. Trade in all the old stuff for Universal Components, and be done with it. Simple, fast, efficient, and puts the gear that was designed into the hands of the players who may still want it.
Sadly, loot gen has outclassed a lot of the old epic items, with ML15 items being able to have +8 stat boons, and 20+ level items going to +10, which old epics were +7, it's actually kind of depressing.
But I guess to each their own. Personally, if they could keep loot-gen in check, then it would find, but I would rather see Challenge/Trade-in type gear be brought in, with the tokens and such dropping from end game chests (Along with maybe other rare named items, and the like) so everyone has named gear quickly after entering the 20's, and then can keep it up as they level.