I know plenty of people who run Titan and Reaver flagging quests because they enjoy them. Their not being an aspect of raid flagging has not made those quests 3-shots for XP and Favor, never to be repeated. If the quests are fun, they will be run no matter if they are no longer needed to reflag. And if they aren't - well, the Dev have added rare drops in quests before to make them more appealing to players.
I would run VoN even if I never needed it to flag for the Dragon again. In fact - they would be more fun without the albatross of needing them to flag around my neck. I'd run Wiz King and Chains of Flame because they are excellently designed quests that are a blast to run. (Offering, not so much)
Right now the flagging is inconsistant and confusing. The persistant reflagging has driven many long-time players away from those raids that require it. Anything that makes the game less of a grind, and more fun is a good thing. We have enough things to grind outside the raids to have to worry about flagging over & over & over & over & over. And hey - if the Devs want to keep some aspects of farming alive and well in VoN... add red scales to the Boss chests in VoN 1-4 with a really super-low drop rate & see how fast their attendance rate soars. People would grind these things, and you know it.
I know, I know.... putting in things players are asking for is crazy-talk. But hey - we like crazy around here.