Hm. So, we have original D&D. Then we get the BECMI game, which adds... um, nothing new.
Then we get 1e, which adds, in terms of new races.... half elves, half-orcs, and gnomes.
Then we get 2e, which adds... nothing. In fact, say goodbye to half-orcs.
Then we get 3e, which adds.... hey! The half-orc is back!
Then we get 4e, which adds... eladrin, tieflings, and dragonborn. The fans go rabid with joy, and 4e becomes the most universally-loved version of D&D out there, never to be repla.... what? It didn't last long?
Then we get 5e, which adds... subraces to every new race in the core book. Every race that's appeared in every core PHB dating back to the beginning (except the eladrin, which are in the DMG).
I don't think "new races" should be part of a core book. You want snow elves? Write one up! There are rules in the DMG for it. I don't really know what a "snow elf" is, outside of Skyrim, which isn't WotC property (and is pretty obscure, even in Skyrim!) New and exciting races that vary from the "norm" should be in setting books or expansions.
In 5e, so far, we've got Aarakocra, Genasi, Deep Gnomes, Goliaths, Minotaurs, and I'm sure a couple more that I can't remember.