It's simply a tweet to say he gets more value from talking directly with the founders about what he wants to know. Seems pretty reasonable to me, but I could see how a certain audience would say ** context and ignore to categorize it as "controversial edgy tweets". Easy to rile those people up though without challenging the algo.
The whole point is that he didn't say it as you worded it, it's always about making a dramatic statement.
When you get into the "riling people up" part - like saying "Thanks I'll definitely listen to him now" in response to criticism of someones bona fides - it's very satisfying, but bad for the soul IMO. It subtly distorts how you view empathy because you're always arguing with a hyperreal snapshot of the other person (and them to you)
So basically it's all fluff as he mentioned it in a later tweet.
Give it to an MBA to evaluate and they will come right back complaining about it. Guaranteed. And asking for a formal business plan with a detailed financial planning.
So, yes, in practice for someone who are familiar with startups it is a business plan. For everybody else it's just a generic description.