Someone should sue FACT for copyright infringement – and refuse to settle.
In US law, there is no such thing. The shape of a glyph (or many) isn't even slightly copyrightable. This is settled law. Fonts (on computers) have a special status that makes them semi-copyrightable in that some jackass judge from the 1980s called them "computer programs" and so they have the same protection as software... but this won't protect against knockoffs.
A font file is more like a config that’s used by your OS to render something, there’s no real interactivity in fonts (except some ligatures but those are just static tables, right?).
I would say that counts as interactivity.