I had a very similar issue. I had a meeting. After it had been completed, I wanted to cancel all future meetings in the series. I canceled, but it canceled everything, including the ones that have already happened along with chat history and recordings. Is there a way to recover the meetings? I don't want to create new meetings, I just want to recover the history.
What I tried.
Deleted Items doesn't have the cancelation
I don't have a Trash Folder.
Recover items deleted ... does nothing.
This is extremely unfortunate. I erased the whole history with one click. This menu is confusing. Cancel series to me means cancel all future meetings, not past. At least you should agree that this message can't be interpreted differently.