Post author here — I'm not affiliated with AngelList at all, though I did invest via one of their RUVs once and was a fan of the experience.
(I'd largely written the post before even being aware of that offering, which is why it's kinda tacked on at the end.)
You could probably improve the article by disclosing this info in the body.
Updated!
That's not a nice thing to say, it doesn't come across like that at all. Just like not every article mentioning Docker is 'a puff piece to sell Docker'. Roll-up vehicles are simply tools available to companies seeking investors.
AL is but one (large) player. Groups of friends use Assure and others (I’ve participated through a few of these companies, and I’ve seen more).