Getting people to use assurance contracts to solve coordination problems seems like another coordination problem. It would be funny to use them for that problem too. That is, get people to sign an assurance contract that they will start using more assurance contracts when enough others sign it ;)
I think that this is similar to the prisoner's dilemma. If A is in an argument with B over some issue, then a contract for them to each update their probability estimates to the average would benefit the group. But each side would have an incentive to cheat by not updating his/her probability estimates. Given A's priors the group would benefit more if only B updates (and vice versa). Unfortunately it would be very difficult to enforce a belief contract.
This does not require them to be selfish. Even if they were perfect altruists they would each believe that it would help both of them the most if only the other's probability estimate was changed.
I tried disabling uBlock, but I was still unable to access it in either Chromium or Firefox.