When discussing system features/status with stakeholders, I've found it can be dangerously easy to shift from concrete certainties to more of a brainstorming, thinking-out-loud type dialogue. The problem is that stakeholders often can't tell the difference between the two and while you're internalizing and assessing the practicality of their request, they're hearing confirmation of the feature's necessity and practicality. Once they have the impression a feature will be there, it is tricky to walk that back. Once I realized this, a simple language shift helped increase clarity:

old: "Idea" -> "hmm, yeah we could...{thinking out loud}"

new: "Idea" -> "interesting, let me look into that, check with some people, and get back to you" or "interesting, there are a lot of pieces to that, how would you prioritize this against {comparable item}?"

That said, it sounds like No Man's Sky team was performing unprompted brainstorming sessions during public interviews, which is really unwise and essentially inviting people to be disappointed...