Calendars where people already saved the event only update if those people subscribed to the whole collection. The location short link is the exception: it always points to the current meeting link.
Subscribed to the collection: Yes. New and changed events of the collection reach their calendar automatically.
Added this one event to their calendar: No. Their calendar keeps the copy they saved.
Has the link and opens it again: Yes. The event page always shows the current details.
The edit form shows this as a reminder: "Updates will not automatically appear for events already added to a calendar unless the user is subscribed to the full collection. However, the location URL will always redirect to the most current link."
Keep attendees up to date
Online events: leave Shorten URL on. If the meeting link changes, the short link in everyone's calendar forwards to the new one. See Add an online meeting link.
Events that change often: share the collection page instead of a single event, so visitors can subscribe and receive updates. See Create and manage collections.
RSVP events: download the registrations and email the attendees about the change. See View, edit and export registrations.
A new time or date: tell people to add the event again from its page. Their old calendar entry does not move by itself.
Cancel an event
To cancel an event, delete it. See Edit, duplicate or delete an event. This is what happens:
The event link: stops working. Visitors see a "page not found" page and can no longer add the event to their calendar.
Calendars of people who added this one event: the event stays in their calendar. CalendarLink cannot remove it.
Calendars of collection subscribers: the event disappears automatically the next time their calendar refreshes the collection.
CalendarLink does not tell attendees that an event is cancelled. For an RSVP event, download the registrations before you delete the event, so you can still email the attendees.
Tip: if you want people who open the link to see that the event is cancelled, edit the event instead of deleting it, for example by starting the title with "Cancelled:". The page stays available with that message. Calendars of people who added the single event still keep their old copy.