Hell of a qualifier....Remember that fictionally the universes our characters live in are, quite literally, splinters from the main Ultima world. So its history is ours to a certain point, and ours has mirrored its in broad terms.
The addition of a global change like Elves isn't a splinter. The sampire template is a splinter.
RP/UO historians have to remember a great deal of UO players weren't into the single-player series at all, which was far from popular in comparison to say the Final Fantasy series (not comparing them based on content, just popularity and series longevity). I'm not saying UO hasn't and shouldn't continue to draw from its history, I'm saying--from the standpoint of someone who began playing UO when it first came out to the time Elves arrived--the whole introduction of a second race seemed like a tacky sideshow, which, apparently, was a decision based on a closed user poll. Wish I had a vote.
Elves never existed in UO in any kind of meaningful way prior to ML, unless they were in A Treatise To a Llama or something. Whether they existed prior to UO doesn't really matter to me because the way they introduced them in UO is the way they introduced them in UO, found in a lost and forgotten tree. I'm glad you found the process more rewarding on a RP level but I found the whole thing to be half-assed. Thankfully the peerless fights were amazing, and the main reason--IMO--to get the expansion.
Anyhow, my point is Orcs have a history in UO which doesn't need befuddling past UO, whether its Tolkien, his predecessors, or even the original Ultima series. UO is going to be 15 years old, I'm pretty sure it's safe to add content based on its own history at this point--like Minax still being alive (bring on the Orcs!).