Early stages of leaf growth can be shed in later stages, yes, but this is minimal.
You will see two types of growers: one which had yellowing leaves all over during flower and the other that maintains the canopy during flower. Some folks insist its natural for the canopy to die off during flower, and it should, but in nature, the canopy only dies after the seeds are finished being formed. Cannabis is a monocarpic plant, meaning it flowers once and then dies. If you pluck off flowers as they form, it will live (theoretically) indefinitely. However, when the seeds are fully formed, they send chemical signals (I prefer to think of it as a conversation cause its cooler that way) to the other parts of the plant, which results in death. Basically, the plant sends its last energy into the seeds in order to give them a better shot at survival.
Your plants, however, aren't forming seeds, and even worse, they are in early stages of flower... Which means something is off.
Its time to start analyzing. Yellowing on lower leaves and new growth is usually N deficiency. Start upping the dose slightly. Small changes! The crisping middle portions of the leaves are something else. Did they get too close to the light? I am less of a diagnostic guy, so you might do well to submit this info to the plant problem pages.
All in all, they look pretty damn good.
