This move might seem stupid rn, but it will pay off in the long-term.
Yes Curry doesn't play Sova, but he can flex onto multiple agents; he can play sentinel and have Mitch play Sova, or play flex and have Xeppaa play Sova, or Curry can learn Sova if need be. Curry's flexibility is gonna be essential for C9 imo, something Xeta struggled to do.
Plus he might follow the T1 trend of letting go a player and said player thriving on another team (seven on TSM, Saya on The Guard, Victor/Crashies on OpTic, etc.)
TL;DR: Curry is good, and his flexibility will help C9 in the long-term.