PvP content can be replayed for years if done correctly. The one thing that Classic WoW lacks is a competitive PvP system. Blizzard added Arena in TBC to try to fix this issue. Arena was not the right solution, and the developers even admitted to it. I understand the appeal of Arena. It is competitive and has a defined ranking system. However, pigeonholing players into a tiny area with pillars is not in the spirit of the game. The game is about the open world and the encounters in it.
The first change that should be made is to split the honor system into battleground and world pvp rankings. Honor earned in World PvP and honor earned in battlegrounds should have separate ranking systems. As we all know, the release of battlegrounds trivializes World PvP, since you can no longer viably rank up doing it. Part of what makes World PvP special is that it can happen in almost any zone of the game. You have 20 or 30 wide open playgrounds where players can engage in battle. The map is constantly changing.
The dilemma is how do you make World PvP more structured and competitive? There are 20 or so contested territories in Classic WoW. Unfortunately, most of the level 60 World PvP happens in Silithus, Searing Gorge, Plaguelands, and Winterspring. Level 60s should be incentivized to PvP in all the contested territories. Obviously, camping low levels in Redridge is not what I have in mind. However, every contested territory should have reasons for level 60 players to frequent them, so that there can be World PvP across all of Azeroth.
How do you add strucuture to World PvP in Classic WoW? Do you turn each contested territory into a temporary open world battleground? What if Tanaris had objectives similar to Arathi Basin with a resource score. The faction which earns the highest resource score wins the battle in Tanaris. What would these objectives be? How would you discourage mindless zerging? Could you have a ranking system based on player performance qnd contribution in each battle?