It's what this early statement from him suggests:
"I'm doing a (free) operating system (just a hobby, won't be big and
professional like gnu) for 386(486) AT clones." -
http://groups.google.com/groups?hl=en&selm=1991Aug25.205708.9541%40klaava.Helsinki.FI
He claimed that his work is "just a hobby" and not "big and professional",
but he nonetheless explicitly compared it to GNU. It looks to me like he was
going to make a whole operating system, but probably not from scratch; he
probably intended from the start for the operating system to be a GNU/Linux
system. If GNU didn't exist, he might have instead used MINIX software or
something.
Then again, when he released something, he *did* say that Linux is a kernel.
