This issue was addressed with improved checks. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1. Users removed from an iMessage conversation may still be able to alter state.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ipados | Apple | * | 13.3.1 (excluding) |
| Iphone_os | Apple | * | 13.3.1 (excluding) |