No. The idea of Blood Elves messing with the Void is a very old one dating back to Tempest Keep, where High Astromancer Solarian could turn into a Voidwalker. It is a concept, the one of Void-infused Blood Elves, that Blizzard had desired to explore for years. In addition, a Void Elf, Alleria Windrunner, was the protagonist of Mac'aree, a Legion zone introduced months before the actual reveal of Void Elves as a playable race, so they didn't come out of the blue, and the writers most certainly did not come up with this concept at the last minute.To bring them as a race was a very poor and sad decision considering that they were probably made up in like 5 seconds.
Unlike Gnomes, who had NO MENTION WHATSOEVER in the Warcraft RTS games, and were invented just because the Alliance lacked a 4th playable race back in Classic.