You cannot judge whether chicken is raw (or cooked) based on the color or the presence of blood. Have to do it by temperature, which if it was sous vide properly, it was cooked and safe to eat.
It is the direct result of younger chickens being sent to market.
Chickens commercially marketed are typically slaughtered between 6 to 8 weeks of age. Outwardly they appear fully mature, but their bones have not completely calcified. As a result, the bone mass is very porous. Deeply colored pigment from the bone marrow migrates to the surface and often is visible along the bone and the meat that is immediately attached to the bone.
Freezing of fresh chickens exacerbates the problem. The marrow expands inside the bones as the chicken freezes and eventually pushes through to the surface.
All that said, the meat still is perfectly wholesome, nutritious to eat, as long it reaches the requisite temperature, or about 160-165F.