Currently users must specify the `notify` clone meta-attribute to `true` to get clone notifications. It's unlikely anyone disables notifications intentionally (which would be worth some investigation), so we should probably default to sending notifications whenever a resource is cloned and its resource agent supports `notify`.
We could change the meta-attribute default to `true` (and potentially deprecate it), or we could drop the meta-attribute and rely on the `notify` action's `enabled` meta-attribute to decide whether to send notifications (potentially with an XSL transform to preserve the existing configuration's behavior).
This would change behavior of existing configurations, so it should be done at a major version bump.