Another one bites the dust!
This type of quiet shutdown has become an expected and unfortunate trend in the smart home space. Running these platforms in-house can sound like a great, cost-saving idea at first, but doing so over months and years appears to be difficult and costly. Customers are then left hung out to dry when the platforms are inevitably shuttered.
Sadly, this is allowed by the terms of service of most of these devices (including smartthings, by the way) – – there is no guaranteed operational period for the cloud features.