[EricH]

For me, the "meta-coopertition" is something like the collusion debate from 2003. In that case, the agreement was to not play defense on your opponent's scoring stacks to boost both sides' ranking. A number of teams said publicly that they would not participate. Others said they would.

It's a bit tougher here, but for this case, I'd call it a team's call to make. It's a strategy. As a strategy, I don't see an issue with it. However, trying to force other teams to join in is an issue, as the GDC noted.

6v0: Again, it's a strategy. I don't see an issue with it, but I do note that it isn't to a team's advantage to go that way, except on the bridges.

With the intentional tipping of the coopertition bridge, I think that might be pretty close to the behavior the GDC commented on. It's not quite there, IMO, but it is saying that "I'm going to deny both of us any chance of the coopertition points." That's (almost) forcing teams to join in. Given that situation, I would expect that some teams would try to push that team up the bridge, taking advantage of the slightly-reduced traction on the bridge--a fair penalty for trying to force your view on someone is that they try and force their view on you, at least in this case.