All assemblages of multiple humans are dysfunctional to some degree.

Sometimes it's worse when a dysfunctional team has to pretend like it's functional.

For example, if the dysfunctional manager reads his first management book and sees the superficial insights but doesn't see the fundamental truths.

"I read that high-functioning teams never have side-channel conversations, so therefore we will have no side-channel conversations".

Now you now have no way to have disconfirming evidence.

Side-channel conversations allow people to de-risk, "am I the only one who sees this disconfirming evidence? Or will I at least be backed up by others if I speak up?"

High-trust teams don't need side channel discussions very often because people feel comfortable flagging disconfirming evidence and knowing they won't get in trouble… but getting rid of side-channel discussions does not make a team high trust.