I actually never had thought of copyrights, but this is an interesting thing
Did some typesetting software once and thus know a bit about this.
Most typefaces are copyrighted and can thus not be used without permission. I am sure that this is the reason Windows is missing my favorite typeface, Univers and I have to survive with Arial.
It is a very common practice to make extremely small changes to a typeface and copyright it again e.g. a "cheaper version of Times" called Tempora does exist.

Just a bit of info

Erik

Erik