The thing about lore is that it is lacking in terms of equipment details... Tolkien did not waste much time describing armour and weapons... he did so only with unique materials, such as mithril... Are we to be bound by this lack of specific lore on the subject?
I think we shouldn't, because a lot of things can be assumed reasonably on account of other factors about which Tolkien was very clear. As I've said in my thread on the matter, Tolkien describes the Noldor elves as the greatest in craftsmanship amongst all races and nations... That single simple fact is enough to do away with the wooden shield for the basic high elven infantry - militia, if you will... Of course, I'm not talking about meddling in units stats, their attack or defense values... simply a matter of aesthetics.
I will go to my grave with these words on my lips - no immortal being, with a cultural heritage of tens of millennia (that includes military tradition unmatched by any force in history other than the Valar's incursion of Beleriand), would be caught dead with a wooden shield on the field of battle!
No matter if he is only 25 or 50 years old, no matter if he was a musician or a dung shuffler in the royal stables... when the ors come a-knockin', the elves would have prepared some kind of decent war gear as part of a emergency provisions programme over the many millennia! Give them metal shields!