I'm just going to point out this change doesn't really make a lot of sense. And before one of you point out this is a "clarification" and not a change. This might be a clarification of lore that was written, but it also a change in how people play their characters.
The reasoning behind this makes no sense. For example: the traits. Okay so if half-breeds reproduce they have a chance of making a pure blooded elf/human. Lemme explain. Uppercase is for dominant, lowercase is for recessive. Curses are dominant, no curse is recessive. So if a half elf has alleles Mm for mortality, and Ff for fertility; that would make them die young and be infertile, makes sense so far. When they breed with another half elf they have a one out of eight chance to get the good recessive traits, and make a 'perfect' half-elf. Also the half-elves also have a 1/4 chance to produce a pure human or a pure elf. See the probrem here? It doesn't make sense to have the races differ by a single allele.
EDIT: Also if this is the lore, People can just say they happened to be the "perfect" halfbreed. And keep the good traits of their parents, but none of the bad stuff.
Completely ignoring the science, this would create numerous plot-holes in the game world. Why did half-elves live so long until Elysium? A lot of characters would spontaneously die for absolutely no reason. It doesn't make a lot of sense when you think about it.