Tedster, let's assume your memory is accurate, since that sounds like a reasonable possibility to explore regardless of what Matt did or didn't say. If this is what's happening:
--Why exactly would that "slow process of new data integration" cause bouncing rather than just a stable shift in rankings? (I.E., my page was #5, but then Google added new, better pages and dropped me to #9.)
--And why wouldn't everyone be seeing the bouncing behavior?