I dont think they should necessarily come up with new quests every holiday. What is wrong with regular quests, easter egg hunts, scavenger hunts, that we can count on and prepare for? What is wrong with setting it up once and for all and having it simply activate on the date in question?
We all know these holidays. A regular holiday quest, items that you can count on (witch's hat, pumpkin head), etc. do not make the season less. Does anyone really argue that you just can't have dinner each thanksgiving, that instead you have to have something else each year? How about, New Years is so trite and boring being at at the same time all the time, lets randomize it to make it more interesting.

Or maybe, presents are so cliche for birthdays, lets stop that and start just randomly making new things to do. Maybe we could insist people having a birthday give up a forearm or something, after all we want to be totally original this time round.
Ok, a little bit facetious, but there really is nothing wrong with having reliability and some tradition to all this. Nor should there be any problem with allowing players access to those things from times before.
And I am not saying there can't be something new occasionally. As I have been typing here it occured to me a Norn May Day with May Pole dancing (new dance emote?), goood special spiced flower cider (Frost Ilboga Cider?), and a kind of Norn Olypics with hatchet throwing, caber tossing, lightning dodging, 9 pins, and ofcourse Charr Mudwrestling! (Where the character wrestles a Charr in an arena that has slow and slippery terrain,

) And we do realize one must be inebriated to compete.
Plenty of room for new things. I didnt really care for the dragon fest quests because they were all Nightfall stuff. I wanted Canthan stuff - Factions stuff in my Factions Festival. <sigh emote here>