I'm gonna dredge this one up from the depths simply because I feel it needs to be reaffirmed. The changes needed to point to each unique racemodel should be made sooner rather than later - in this way, art assets can simply be plugged in as they're created, rather than waiting on client and server-side changes to enable them for the final release. And in support of "duplicated" file-content, I would say that until official assets replace them, at least this method would allow for player-created content to 'fill in' until that point.
Concession: I do concede that to do so would increase the download size with no visually-apparent gains, save the enabling of future content.
Disclaimer: I am not suggesting that player-created content should be relied upon as appropriate 'filler' but I am in full support of anything that allows a player to tweak the game to their personal preferences, and if that means reusing Ynnwn or Derm models for a temorary Diaboli or making visual changes to the KlyrosM and resaving as KlyrosF, "until we have something better" it has my endorsements.