I think when the target of the agreement is a spin approach or topic that should just be avoided I think the common has a already established name - a taboo.

It would also seem that it would be against the journalists integrity to participate in such in a big extent. If a laweyr would be only allowed to sue if the verdict would be "not guilty" many would not take such an ararngement to fullfill proper legal investigation. But then again if you phrase it as a plea bargain it sounds a lot better. To the extent I would view this positively is that it woudl make a person willing to share details on a hot topic issue they would not otherwise share. It better for the issue to come out even if it accompanies a spin. It would also ensure that there ared atleast somen steelmans in the discussion getting space. But by large precommitment to opinion I see as a thing wrong with press, not something to be strived for.