That's how it got to $1.2 trillion. According to other stories I read this afternoon, Pelosi hasn't been able to find 218 votes to pass the bill, so she has agreed to add things to the bill to try to make it more palatable to some reluctant House Dems. The problem is that none of these new costs are paid for by taxes or spending cuts, so it doesn't sound likely this bill will be acceptable to moderate Dems unless Pelosi is able to find about $300 in new revenues to cover these costs. I've read a lot of stories that reference this $1.2 trillion cost, but I haven't seen any that explain this apparent increase as the result of a change of assumptions as you claim, but if you have a link to such a story, I'd be very interested in seeing it.
The article explaining it was already posted earlier in the thread, but I'll do so again:
The Congressional Budget Office said Thursday a U.S. House health-care system re-write would extend health insurance to 96% of the nonelderly U.S. population by 2019, and spend $1.055 trillion to do so.
Penalties imposed on individuals who did not purchase insurance, and employers who did not offer coverage to their workers, would raise $161 billion over that time-frame. That brings the net cost of the bill to $894 billion through 2019, CBO said.
House Democrats have seized on that net cost figure to claim that their bill is below President Barack Obama's upper limit which he set for health-care legislation of $900 billion.
CBO Puts House Health Bill Total Cost At $1.055 Trillion