a lot of the revamped content ride on nostalgia to be honest.
Divine Might was the shit 10 years ago. It was once the hardest alliance BC out there and somehow has a special place in most player's hearts/minds. Just like how Kirin has a similar effect.. and Fafnir. Kirin was already rehashed in VW (Qilin) and nothing strokes Fafnir nostalgia more than a free Ridill. Just having a new reason to go back and fight DM is good enough for me. I hope they do the same for other old missions and alliance BCs (ie. Bahamut). Hard mode BCs is very much like the revamped events (Limbus/Dynamis/Nyzul/Salvage/etc) except that less is being revamped lol. I'm still holding out for them revamping WotG stuff. It may come eventually.
There are a bunch of other things they didn't mention in the video in any case.. but they're mostly adjustments.. new Adoulin quests, adjustments to Assault/Salvage/Meeble entry requirements, iLVL119 AF (which is kinda interwoven into high level battlefields), mog gardens for all instead of just SoA, and access from 3 cities, new BST pets.. and so on.
..on that note tho, very little from this Dec update actually comes from Adoulin proper.. but its not a big deal since we got 3 updates in 3 months. If we followed the old 3-4 month update schedule, i'd say the combined content from these 3 updates surpasses that already.