Your first two points seem legit, but if you pay attention to the measurements they're taking it's pretty easy to notice that your periodontal pocket depths inc

Your first two points seem legit, but if you pay attention to the measurements they're taking it's pretty easy to notice that your periodontal pocket depths increase or decrease based on whether you've been flossing or not (mine do at least). And it's pretty obvious that deep pockets are a decay precursor.