in my opinion Linux couldn't and still cannot exist without
certain
parts of gnu project including software and licenses, especially gcc,
glibc, gpl and lgpl. and that's true for android too, unless it uses
kernel header's without gpl licensing instead of glibc.
At the time Linux was created the were several other suitable compilers,
the original Linux C library was not glibc and the original kernel
license was not GPL. UZI didn't use any GNU tools in its base either, nor
OMU. So not only was it possible, it had been done.
Android doesn't use glibc either.
The FSF did some very important things - codifying what was already
practise, figuring out how to stop abuse of that practise and having a
grand vision of what all the pieces could mean.
Alan