There has been clear communication to the Signatures on this fact. They've relayed it to the forums which is one reason we're discussing it. AlMc among others have confirmed this multiple times.
I'm looking forward to a slower ramp more than I thought I would. It'll be nice to take my time and digest all the (hopefully wonderful) things that owners are saying.
I think the point he's making is that Tesla hasn't reached out to Signature res holders on their own. All the confirmations we have come from folks asking Tesla. There will be a group of Signature reservation holders who don't hang out here and won't ask Tesla about the seats; they'll just assume the seats fold and won't know that there's been a change from the initial prototype design specs until their car shows up.
But, yes, there's no question the seats don't fold.