The game entered closed beta in late February, and developer Psyonix noted that Early Access buyers are gaining entry to the closed test phase. It recommended players on the fence to "wait for Open Beta and play Nosgoth for free" when it reaches Steam's free-to-play section. Once in open beta, the Early Access founders' packs won't be available for purchase, but the content will be valid for previous buyers.
This isn't the first time a publisher opted for a low-risk Early Access release on Steam. Kasedo Games brought Hegemony Rome: The Rise of Caesar to Early Access in February and Ubisoft launched alpha versions of Might and Magic X: Legacy in August 2013 and The Mighty Quest for Epic Loot in November.