You can even take it a step further. Ramp up your intramural program and give them field space.I agree parents have the right to be upset if the communication conveyed a starring role. I'm talking about when there has been no starring role communication but parents think their kids should have a starring role, then team work be damned and let it be rec soccer all over again with equal playing time even if it's varsity soccer.
If we want to build more playing time for everyone in high school, keep the JV team alive for seniors too. Let the JV team be the one where results don't matter and equal playing time is required. The problem occurs when parents want their kids in varsity because they think they've paid their dues for 3 years in JV.
If you have solid frosh, jv, and intramural programs available with adequate field space, then you've been fair. Most kids will be too busy playing too complain.
If varsity hogs the field space, then you haven't been fair and you should expect complaints.