Show me any post that recognized that preexisting was a separate mandate/requirement.
To answer the other question. In the olden days it came down to a combination of charity or death I suppose.
It still is, but the government has taken over the role of the Church. If the Church had insisted on holding onto that role, the churches would be filled on Sunday and people would be more active in the church. In many ways, the church community acted as the health care insurer for its active members. When people in the church got sick, they'd take up collections or they would use funds set aside from the general fund. People don't need the church anymore. People now look to government rather than God.