MANY of us create and maintain local libraries. Even if the KLC said something like, “Creating circles from two or more arc segments is encouraged.”, I’d probably still use circles because they are easier to create and much less error prone. If I used a standard KiCAD library footprint as the basis for my own footprint, and found a circle made from arc segments I’d be inclined to convert it to a real circle.
Since the problem is known to be related to outdated CAM software used by a relatively small number of fab houses, it’s reasonable to expect the problem to resolve itself in the future. I’d argue that the most correct solution for KiCAD is an informational dialog popup displayed when you plot a Gerber silkscreen layer. It would say something like, "This silkscreen layer uses graphic circles. These may be rendered incorrectly on boards produced by the following vendors: . . . .
The python script circles2arcs.py can avoid this problem by converting silkscreen circles to multiple arc segments."
Dale