I don't think that it is. I know that at my university I only encountered anything with the OS in 3 elective classes (OS, UNIX system programming, and networks).
Lots of lower tier CS programs like mine seem to really just focus on popping out Java programmers that can work on enterprise systems. Probably 33% of my graduating class fit that bill and went to work on low importance systems at a local bank.
> Lots of lower tier CS programs like mine seem to really just focus on popping out Java programmers that can work on enterprise systems.
Even in higher-quality ones, OS (and thus syscalls) may not be covered if the curriculum focuses mostly on, say, computational science, or PLT, or formal methods.