Yes, yes, yes, and yes. That's what happens when the company pays most or all of your health care expenses. He who pays the piper gets to call the tune.
Unless of course the law indicates otherwise, which it often does in such cases. In the US you can't discriminate against old people, black people, or on account of race, or in some jurisdictions on account of sexual orientation.
I have worked at my job for 19 years. Do you believe the owner has the right to now change the terms of my employment and insist that I give up snow skiing, waterskiing, target shooting, hunting, my sports car, my beer-drinking and my occassional cigar, or else be fired?