I will turn in my Plan 9 install media and my copy of The Design and Implementation of the 4.3BSD Operating System at the nearest DEC service center.

I remember that in 01998 or 01999 I asked Andrew Tanenbaum, a different European CS professor, what he thought about Linux. His impression was still that it was some kind of hobbyist project for people who (paraphrasing here and reading between the lines) couldn't afford a real computer. So I suspect that, even when Caml became OCaml, its developers saw Linux as belonging to the same crowd as Microsoft Windows, rather than to the systems they were used to.

But even that Windows/Unix OS dichotomy didn't exist when the programming language was designed. They might have been thinking about Unix vs. VMS, or Unix vs. GCOS, or Unix vs. Oberon, or BSD vs. System V, but definitely not Linux vs. Windows.