Since the penalty is unenforceable (though the IRS is charged with collecting it they lack statutory authority to actually collect it except by withholding returns). Paying the "penalty" is actually optional which is why it was allowed to pass a Constitutional test.

Expanded Medicaid is already going away without any change to the law. The additional federal funding for the expansion was time limited (which is why many states rejected it). The states that expanded it are now looking at a serious budget problem. This is another major failure of the ACA as a concept because virtually the entire so-called 20 million (though that number is a lie as well) uninsured that are now covered is in Medicaid. By the way, the individual states essentially determine the eligibility for Medicaid so even without the ACA states don't have to retract coverage. All the ACA did was TEMPORARILY increase the matching federal funding beyond previous income levels. It was all smoke and mirrors.

One more salient point, the number of uninsured today is virtually unchanged from pre-ACA. The entire law was a complete and total failure by any real measurement.