I don't know how data driven it was, but an accelerator I was in a few years ago said that they found that their seed stage startups with early revenue actually had a harder time raising a series A in many cases.
Presumably due to the fact that VCs would try to extrapolate future market from that revenue or would wonder why the revenue wasn't higher already.
But if you were "pre-revenue" then they just accepted that you were pre-revenue by choice and everyone's imagination was the limit for future revenues.