Biologically they are all High elves, as in Thalassian elves. It's just that some are Void-infused, while others are Fel-infused, and so on. And that's why Ion said that both Void elves and Blood elves are indeed variations of the original "High elves". Just like the green orcs are still orcs, or the fel-infused eredar (man'ari) are still eredar.
But politically, the Blood elves will never be the "main" Thalassian faction, simply because their claim to Quel'Thalas is challenged by the Ren'dorei and the Silver Covenant. And this has been the case since forever, even before the rise of the Ren'dorei the Silver Covenant denied the Blood elves' rule on Silvermoon. Vereesa even told Theron that he had no right telling her what to do, and that Quel'Thalas was still her home too.
Regardless this debate has gone on for far too long, all that's missing now are additional customization options for Void elves, which will come in time.