An event gets removed from the website if:
1. Event status property has a value other than "H", "I" or "O"
2. Period does not have odds
3. Period cutoff property is in the past.
Please note that an event can also be deleted. This rarely happens so we don't provide explicitly this information in the API.
To detect if an event is deleted or settled, the client would need to call Get Fixtures snapshot (without the since parameter) and if an event is not present in the response it means it is settled or deleted.