I sort of want to just say Poppycock to this. How many billionaire dropouts do you know? I don't know any myself. OK, fine if you happen to be connected in SV and know MZ or whatever then you're an outlier.
These billionaire dropouts like Zuckerberg and Gates, ... where did they drop out from? Although I don't think it makes a lot of sense to equivocate those two, it will suffice for now.
I don't think times have changed that much. Learning purely from these things is also going to be likely only for autodidacts. There happen to be many of autodidacts in our little world (or at least autodidactic enough to put together a website in Rails or something) but this is not true of that many people.
In fact, how far do you get with this online stuff? Not far, if you look at most places like Khan and so forth, you're talking about sophomore, maybe junior year stuff for the most part. OK, sure there's the occassional machine learning course that gets popular online that a lot of people that don't have any sort of mathematical background take and can say they are a part of the "cool kids" group, but let's be honest. Even then, we're still talking about this small segment of autodidactic or semi-autodidactic types.
A lot gets said of "big bad college" and how the "fresh new hip information revolution trumps traditional learning" but I don't see it. Sure, you could put up a few tutorials about learning to make Hello World in Javascript but I'm just not seeing this education revolution here.