The full CBO report on the result if HR2 becomes law (Repealing the Job Killing Health Care Reform Law Act, I guess RJKHCRLA; you've got to have an acronym) is here.
It is not hard to figure out that since CBO said the passage of the ACA would reduce the deficit from current law at the time of its passage, they say unpassing it will increase the deficit from current law, which is the ACA. Various groups saying that CBO said that passage of RJKHCRLA would decrease the deficit simply took part of the CBO report (getting rid of the subsidies for private insurance and Medicaid spending). The other side of the equation is increases in taxes and cuts to other spending, namely Medicare. You really either have to take CBO as a source of information or say they are not, you really cannot with a straight face only take part of their report.
In 2021 with RJKHCRLA, there will be about 33 Million fewer people with health insurance than there will be in the ACA is implemented. With ACA, about 95% of the population would be insured in 2021, with RJKHCRLA it will be 82% (today is about 83%).
Given that the Republican party seems to be opposed to expansions of government insurance, an employer mandate, and now an individual mandate, I don't think they have a credible health reform strategy that includes addressing coverage and cost. If they do, I would love to see it/hear about it.