Ability to disable PR notifications for all the users in a workspace

Currently, if the users from a workspace do not want to receive notifications from Pull Requests from that specific workspace, each user has to manually change their notification settings in Personal Settings.

Users that are set as default reviewers, for example, are automatically assigned as watchers in Pull Request and this can lead to a lot of emails being received.

It would be great if there was a functionality where users could choose to enable/disable the notifications for pull requests (existing and future PRs) in a workspace. If a user disabled notifications for Pull Requests, they would only be notified if they were directly @mentioned in the Pull Request.