Durational-residence requirements still exists. E.g., paying in state vs. out of state tuition at a state university, which commonly requires a year of residency. [0, 1] State-provided healthcare could be provided in a similar fashion through state-administrated health insurance that has different rates for in state and out of state. There could be a durational-residence requirements for in state pricing.
"If the purpose of the requirements was to inhibit migration by needy persons into the state or to bar the entry of those who came from low-paying states to higher-paying ones in order to collect greater benefits, the Court said, the purpose was impermissible"
It's obviously hard to know for certain what SCOTUS will do, but under that standard it sounds like having health care benefits only available to long term residents would be on very shaky legal ground.
[0] https://repository.law.umich.edu/mlr/vol104/iss3/5/ [1] https://www.law.cornell.edu/constitution-conan/amendment-14/...