You can defer the decision without waffling on the communication. Saying "we'll decide this later" (ideally with some reasons / parameters), is decisive - and sometimes gets pushback. Going silent in order to avoid dissent is bad form.

Not to say this "technique" isn't useful, but imo it should be super limited. I'll put off a reply when a) it's a non-urgent issue, where b) resources (documentation, or other local users' experience) exist, c) this user will be motivated to find them (by the nature of the issue, or because I know they are the sort of person who does that), and d) independent problem-solving will fulfill a teaching function. Even then, I will hit "Snooze" on the email and follow up a day or two later: if they haven't solved it I'll point them to a resource; if they have I'll praise them for figuring it out for themselves. People like both outcomes.

I notice that many of the historical examples are a result of latency in communication, like people asking for things that had already been done. We don't often face that constraint.