Blizzard will likely do neither. Two reasons. One, the blue/purple skin tones are thematically appropriate for a Void Elf and were a deliberate choice to distinguish them from Blood Elves, Blood Elves having the human range of skin tones.
And two, human nature being what it is, giving human range skin tones to Void Elves would mean most Void Elves taking that customisation rather than thematically appropriate blues or purples. Void Elves as a group would lose something distinctive and they have a right to be their own thing, not forever treated as the next best thing to a high elf on the Alliance and made to suffer for that.
Did they say the human range skin tones were possible on Void Elves? Yes they did, just as Ion Hazzikostas said in 2014 that High Elves (without modification) were a possible sub-race. Only when they sat down and worked through the implications did they seemingly create Void Elves as an alternative, just as when they sit down and think through the ramifications of normal skin on Void Elves that they will probably back off.
Instead, I see it being likelier that Blizzard could provide alternative skin tones similar to the doctored images you posted previously, of the partially normal Void Elves who are mottled and disfigured with the void. I call those the monkey paw result. If anything happens to the Void Elves in terms of tones, it would likelier be that.
Although I say again, they should use the opportunity of a Void Elf customization pass to lean into the void fantasy rather than duplicate the Blood Elf one. They could give the Void Elves some pretty nifty monstrous options.