That is the one thing Blizzard will not do, they may tweek with a race so it is hardly the race we think it was.example: Dreanai, turned into good eredar. However the race was fully in lore prior to the mashup.
The Lost ones were the Dreanai of WC3, Dreanai were stealth scout units. Eredar were the leaders, and warlocks of the Burning Legion.
That is the most I would expect.
Sort of why I think the reality is Half-Ogres, and Half-Elves.