There are two ways to nerf an old dungeon:

1. You flat out make it easier, lower hp on mobs, easier mechanics, or dumbed down mechanics, or mechanics that just hit less so you can get hit by them and live easily.

2. You release new content where the gear is so much higher than the old content that you can wear the new gear and go face roll the old content.

I'm pleading that you do neither SE. If there was one thing I hated about wow, it was how they released their expansions and killed off relevant and (FUN!!!) content. If you make new content that out gears the old content by to much the old content becomes useless and the player base will stop running it.

I want to see 10 expansions come out and still have a reason to go run BCB and still want to go run BCB.

WOW is a huge game, but so much of their content is useless, you don't even see it, and you don't run the raids unless your doing it to kill time or fill achievements from previous expansions.... E.g. IceCrown Citadel was my fav raid. But I bet if I went and got Mists of Pandaria no one would run it with me because it's useless.

Please don't do that to Eorzea. If anything make content in Eorzea more relevant.