The question "Is pi the same in all universes?" is poorly defined. You're talking about pi as "the circle constant for whatever universe I'm in", whereas the G

The question "Is pi the same in all universes?" is poorly defined. You're talking about pi as "the circle constant for whatever universe I'm in", whereas the GP is talking about pi as "the circle constant for a very specific geometry (that we once accepted as representative of the universe we're in)"