Online calendar software such as Outlook and Google Calendar always removes canceled events, once you accept the cancelation notification. That's often reasonable and fine. But sometimes, especially for recurring events, it is helpful to see an explicit notice of the cancellation. E.g., I don't have to get to work early next Thursday, because the weekly coffee club isn't meeting.
It is a somewhat esoteric feature, and probably tricky to design the UI for, but it really could be nice, for some of my use cases. One way I can think of to implement it is for the calendar to ask you, when you accept the cancellation, whether to hard-delete or logical delete. And then it could include an option for "don't ask me this in the future".