I could see it going either way.
With free access, people would be more inclined to go to the doctor for simple and small things, but in return would probably catch more serious issues early and have better access to treatment, therefor reducing the need for intensive and specialized healthcare.
Without, people avoid going to the doctor for small stuff, but end up having to go in with more complicated issues later on.
Heres some studies if you want to do some reading:
Impact of Universal Health Care Coverage on patient demand for health care services in Thailand
The Economic and Social Impacts of Providing Universal Healthcare in the United States: A Rapid Scoping Review
The impact of public health insurance on health care utilisation, financial protection and health status in low- and middle-income countries: A systematic review