More pointless flavor changes, and since it's from an FR source, yet another retcon for the Realms. *sigh*
The "point," of course, was to replace one idea with a better idea. Whether it worked or not remains to be seen, since we're probably only talking about a few lines in a book none of us have read yet.
I'm not sure that the old-model aasimar really fit in the new cosmology, since angels have been so dramatically reimagined. But establishing that they reincarnate . . . that's interesting, isn't it? Is there any other race in 4th Edition that routinely reincarnates? This gives devas a perhaps unique niche that aasimar just didn't have.