Good old times... sadly that kind of event would be, I'd say completely impossible on the live servers.
But if they had old game version somewhere and could run a separate server, Prophecies only, I would certainly play that!
Everyone start from point zero again. A separate world free of the crap that's happening now.
Oldschool GvG's the way of first World Champs!
But still the hardest part would be determining what game improvements, balance changes and nerfs should apply.
Some skills of the past were incredibly broken, having this turn into a degenerate 55hp Protective Bond solo UW farmfest wouldn't be cool. Or spirit spam and Iway at full power in PvP.
Probably the best and easiest way to do it would be just using current game build, just run a fresh new completely separate server with only Prophecies content enabled. There were huge loads of positive updates that happened to the game since earliest times but some are debatable:
*Include Sorrows Furnace or not? - some would agree that the game wouldn't be 'oldschool' with all the greens there. But more content is better and SF was fun to play.
*Tombs of Primeval Kings oldschool entrance to HoH or PvE dungeon? (B/P farm farm farm and every warrior has Victos Bulwark+Axe) debatable.
*Include the HoH global tournament at all? Holding HoH would be piece of cake on a sever with very low player population.
*Locked Chests? or unlocked barrels/wreckages?
*Insignia for all Armors? - probably better yes, would make more sets viable.
*Hard mode enabled? - this is very debatable and dangerous.
*Loot scaling? Maybe only in hardmode? Again comes the problem of the game degenerating into solo farmfest.
*AoE mob spreading? - imho should work as today.
*Any Titles? - imho they wouldn't hurt and would give more things to do, nice to be the first Protectior of Tyria on the server

or a Vanquisher later if HM enabled at all.
*Favor of Gods issue - free access to UW/FoW ? Based on titles maxed? Or
*End of FoW and UW chests - drop inscribables? That could actually turn pretty interesting if the only inscribables on the server came only from them. +15^50 "Strength and Honor" 100k ok?

Or maybe it's just better without them at all.
hmm maybe there should be a separate thread for discussing this?