Perhaps we're spinning our wheels about the term "free range," for there are multiple definitions and confusion, definitely not just among newcomers to chicken raising. Here's an excellent article covering all the meanings (including USDA misappropriation of the term) we've discussed in use today and in history:
https://en.wikipedia.org/wiki/Free_range
Looks like the presence or absence of fencing does not determine whether animals are truly "free range," though in most people's minds, the size and foliage and sunshine availability of the enclosure would matter.
In our remote rural area, we have actual, legally-defined free-range cattle wandering over the desert. Homeowners must fence the cattle
out if they don't want them on their acreage, so the cattle encounter barriers. They also are restricted by cattle guards over roads, fences around the state lease grazing lands on which they forage, and at times, corrals into which they are herded by their owners.
No matter how widely a cow or chicken (or even a coyote) can roam freely, eventually there will be a fence.