Curtains for the Many Worlds Interpretation?

Following up on last week's death knell for pilot wave theories, Quanta magazine takes on the many worlds interpretation.  The quantum Russian roulette thought experiment is a particularly compelling argument against MWI.

Crazy question: Wouldn't these diverging universes have some residual interaction with each other?  Gravitational, at the very least?  And if so, then why don't we see any signs of these interactions?  (Apart from than some possible hand-wavy allusions to dark matter and/or dark energy, I mean.  Show me some math about that and then we'll talk.  No, I didn't think so.)  It's this apparent lack of residual interactions that has always put me off of MWI and related ideas.

OK, on to more positive things, about which we can actually make non-nonsensical statements.   Maybe do some coffeeneuring this weekend.