In some facilitation cases, it is usefull to hide the contributions of the members, to avoid collective bias between one another, for a period of time.
(in synchronous life, the use case is to ask people to write their ideas on a personal paper or post-it, and to collect all of them at the same time).
In polls, this possibility is clear as you have the option to show the results only after the poll is closed.
In the same perspective, could it be imagined one day to add a feature in order to hide the contributions on a certain topic until it is unlocked by the moderator?