You can kinda play one already in the EA, just accept that Haslin comes with you dealing with the leaders. He join the party as a temporary companion.
He's a bit bugged thought, as he can't target himself or others with his healing spell. He also doesn't have many spells known, the wildshape isn't true to 5e, he can cast spells while in beast form despite that being a level 18th ability, has like 8 level 1 spells (should top at 4) too. Way too much HP for his supposed level as well. He's a pretty busted character...
Anyway, they are clearly working on it. Just like the Duergar race.