I've interviewed at Facebook 2 1/2 years into my career and have an open invitation to interview whenever I want without having gone to a tier 1 university for undergrad or grad (although I went to a prestigious program for grad math, UIUC) - my education turns out to be a poor indicator of what I can do.
A caveat is that I originally entered FB's pipeline through a referral from a friend who interned and works at FB right out of CMU computer engineering. Referrals are often enough at these big tech companies.
I'm quite sure it's not true. There are at least 2 engineers from the React team who have dropped out of "normal" schools/colleges in their first years.