Our building was originally a rental, but converted to co-op the end of 1987. I bought my apartment in April 1988. I think there are still a handful of original tenants/renters in the building, but for the most part, we're all owners.
As for that report you found, Nassau County is Long Island, and not within New York City limits, so unless it's a state-wide regulation, wouldn't necessarily be the same for those of us living in the City.
Also, as far as heating and cost, most buildings, though not every single one, supply the heat, but we don't individually pay for it. Heating costs are part of the building's maintenance, and that cost is shared by all, so it's on our monthly Maintenance Bill. Only separate bill I have to pay is for electricity, as that amount varies from user to user, depending on how much you use, especially during the summer months.