Hi, I'm andrestaltz who Elon answered on Twitter. Like others have mentioned here, it seems like Elon is referring to the link layer between the satellites. "Peer-to-peer" probably meant "without a network switch".

I wish I had originally tweeted "... peer-to-peer connections within Starlink-only customers" because I was actually interested in knowing if Starlink could be like ZeroTier. https://zerotier.com/