I think there is a risk to the texture based on my personal experience. Also Sous Vide everything has done some experiment with sous vide direct from frozen and they found it was much worse. They actually did 1) never frozen, fresh steak, 2) sous vide cooked and then frozen and reheated in sous vide, and 3) straight from freezer to sous vide. All were seared after the final cook whether it was the original or reheat. They ranked them 1, 2, 3 in that order and all commented negatively on the texture of #3.
