It's a great idea - grass-roots investment is very appealing - but unfortunately I think the main thing that angels bring is not money but contacts and experience.

This might work with YC-alumni, though they probably they probably don't have enough contacts/experience yet... but they definitely have quite a bit already, and it's growing, and will only continue to grow.

In fact, far from being a result of this meeting, this growing power is one of the causes of it (as noted in the article.)