Serious question: do you really believe that millions of people actually get their policies get cancelled when they actually get sick, for no reason other than they got sick? That seems quite improbable for dozens of reasons - not the least of which is that in addition to all of the state laws prohibiting rescission, the fact that doing so violates the terms of virtually every health insurance contract in existence and courts can and do enforce the terms of contracts, the contracts only permitted rescission in the case of deliberate and material fraud, virtually all rescission cases were subject to outside review...as of 1996 or 1997 the Health Portability and Accountability Act prohibited it at the Federal level for the rare cases that weren't covered by other statutes.
If you meant people with pre-existing conditions who could not get insurance, people who failed to disclose pre-existing conditions and were subsequently denied coverage, people who let their insurance lapse, etc then it's plausible that the number could range into the millions, but it would be interesting to see the actual data.
cue personal attack against JayB and his family in 3... 2... 1...