[aboodman]

As a user of CF workers, the API is clearly designed to allow the runtime to redeploy e.g., for patches.

Example: there is no notification when your worker is unloading. It just dies. This is sometimes annoying as a developer, but it's the kind of decision a platform makes when it wants (needs) to be able to shut down code arbitrarily and restart it later on a different version of the platform.