As an example, let's take this task created in a private space: https://phabricator.wikimedia.org/T114925
The initial log:
Qgil created this task.Via Web · Wed, Oct 7, 6:25 PM
Qgil added a project: Developer-Relations.
Qgil shifted this object from the S1 Public space to the Restricted Space space.
Qgil added a subscriber: Qgil.
Semantically speaking, what that log says is that the task is created in a public space, then associated to a project, then moved to a private space.
This made me think that perhaps users watching that project or receiving notifications via Herald could be notified about the creation of the task before "shifting" to the private space.
I tested and no, the behavior works as expected. But anybody reading that "shifted this object" sentence and really caring about the reliability of their private spaces should feel confused as well, and they might waste the time I spent running the tests.