I believe teams hold Russian player's rights until they're 27, actually. Nikita Gusev was drafted by the Lightning in 2012 and has never signed a NHL contract, but the Lightning and Vegas have held his NHL rights, with one more year remaining. Since he was born on July 8th, he won't be eligible to sign with a NHL team until July 1st, 2020.
It would be nice if Shestyorkin or Sorokin were UFA this summer since the Red Wings are one of the teams that need to look for a goaltender of the future and would be able to provide a heavy amount of starts to a young goaltender with great upside.