Thanks for this rec! I'd like to explain why this is not the case, and why similarly, there's no CREATE action for a device.
Devices in this sense refer to the physical hardware, so the concept of CREATING or DELETING a device is awkward. This is unlike a Docker cluster, an EC2 instance, a virtual device of some kind, etc. which could be CREATED or DELETED on a whim, which is where I imagine the expectation arises.
getDevice & updateDevice (or even better, getOrganizationDevices & updateDevice) manage the attributes of the device, but the resource itself is never created or deleted. Although, that would be a pretty powerful operation if it could CREATE an MS355 out of thin air. Sign me up!
Dashboard claim and release operations are represented in API as functional resources, rather than CRUD operations, which is an accurate depiction of what's happening. Forcing functional operations into the format of a CRUD suite can be awkward at best and confusing at worst.
In short, not every REST operation is part of a CRUD suite! I hope this helps.