I don’t know. As an open source developer I put the onus on myself to make sure my releases (at the very least, not every commit) at least compile and run on Linux, macOS, WSL, and FreeBSD even though I don’t use the first two.
I mean... you just named two enormous platforms that you should test for but don't use. FreeBSD is hardly equal to either of those. It's a much much different situation.
Then the GNU folks could use it or ignore it but they wouldn't be ignorant of problems.
In fact for many issues timely notice is almost all it takes to get things fixed.