No Eric founded Flutter at Google. However, Google had previously acquired another company called Flutter, and they had that domain lying around, and decided to use it. That's what I understood, at least.

Gotcha. To use "Founder" then seems like a weird choice? I guess, I must catch up to the changing meanings of words used in SV.

The canonical way to say this inside Google would be closer to "I created the Flutter project and launched it externally" instead of "founded"

founder is a word that exists outside the context of SV and has never exclusively been the domain of startups.

Guess you're right. Establishing a "Flutter org" counts. Though, I've never seen folks in this space (Bjarne Stroustrup or Anders Heljsberg for example) say they're the "Founder" of XYZ language / framework.

https://dictionary.cambridge.org/dictionary/english/founder (n)

  someone who establishes an organization

Correct.

Are you by any chance also a famous poker player? ;-)