In my specific case, yes. They have read & write permissions over the events in that workspace. Plus, they are subscribed to that event.
The "modus operandi" was the following. When creating the event, only user U1 was Subscribed and users U2 to UN were Invited (with "subscribe invited people" option activated).
In the end N+1 users got subscribed (me, U1, and U2 - UN), which is as expected (no problem there).