I just tried this out of curiosity, but it never asked for my phone number (not only was it not required, I didn't even have the option to provide it at any point during the sign up process). Facebook had no friend recommendations for me at all.

I then tried adding my phone number to my profile (a phone number that I also have on my actual Facebook account). Went back to the home page and looked around a little more, still no friend recommendations. It's actually a solid possibility that nobody who has uploaded their phone contacts to Facebook has me as a contact (I didn't even know that was possible, actually).