The normal usage of the term "Lean" (ie from Toyota) actually has little to do with validated learning and more to do with the elimination of wasteful aspects of production that don't directly lead to customer value. Usually that means "pulling" work out of a team based on need rather than trying to anticipate need that might never materialize (like the need to scale workforce and infrastructure, which is the case here). FTA: "The idea, he says, is to be “global from day one and have scalability built in.”". Of course in any pull system, validated learning is built-in, because new customer demand is new information, but the focus of Lean is actually the reduction of wasteful production. He'll have wasted a lot of time/money if demand doesn't match the infrastructure he's built.
In this context, its about eliminating waste through validated learning.
You are spot on. Unfortunately the 'Lean Startup' book basically overloaded a lot of words around Lean. I love the concept in the 'Lean Startup' book, I also love Lean methodology in manufacturing.
But it is confusing as hell to talk to people in both fields becuase a lot of words have different meanings now.
I recall reading in someone's book - maybe Blank's - that Lean Startups can help when there is market risk, but not "innovation risk" - will the team actually be able to create the thing they have in mind? Something like a new cancer drug was the example - the market is not a problem, the problem is whether you'll be able to create it.