Klokov posted a video on youtube a while ago showing his flexibility during warmup. He's obviously much more flexible than is necessary to reach a snatch position. Does this degree of flexibility have any translation to strength and power? If so, what are the physiological justifications for this? Is there more "room" for muscle fibers, or something like that?
Having the minimum flexibility necessary to do something is suboptimal in a number of ways.
Well, for example with Olympic lifts, specifically the Overhead Squat, being flexible is going to give you better form, better muscle contraction, better hand-grip positioning, where the bar travels, how far back or forward it goes.
Being flexible in the areas of your body that are ball and socket (i.e shoulder, hips) is important in any strength training protocol.
Muscle flexibility in chest and shoulders allows for greater range of motion, which correlates to more movement, which means more time under tension, which means more strength, and explosive potential.
I'm not a scientist or biologist or physical therapist so I'm unsure of any real science. But this is my not-so-common sense answer.