Ultimatum games [1] are a subset of prisoner's dilemmas. That covers Nos. 1 and 2. Assuming researchers want something from those they disclose to, it makes sense for them to cast the widest net possible while minimising the risk of defection. Balancing that optimization is a game as old as civilization.

> This turns it into a security monopoly where the big vendors get exclusive rights to embargo and exclude smaller vendors and control the disclosure process on their own schedule.

Not necessarily. It turns into a monopoly of those who can show themselves to be credible partners. This exhibits incumbency bias which in social context we call track record. It's not nearly as exclusionary as you're making it out to be.

> Then there's the assumption that the monopolised vendors are trustworthy which is 100% impossible to validate and therefore invalid

This is common in trust problems. You don't need to be 100% sure everyone you're dealing with is trustworthy to work with them because we don't live in a single-iteration game. Again, iterations of retaliation and forgiveness remove the need to have 100% certainty about a player's intentions.

[1] https://en.wikipedia.org/wiki/Ultimatum_game