Bundle uninstall only removes the BundleRevision from the runtime if it is no longer in use. The classloader associated with an uninstalled bundle that is still in use remains active.

Approach #1 - "in use" semantic specific to Bundle deployments

An undeploy management operation undeploys the bundle revision but holds in the MODULE phase when the revision is still in use
This is similar to deferred MODULE phase for deploy operation
in use is not respected for non-osgi deployments and hence breaks bundle deployments that depend on them

Approach #2 - "in use" semantic applies to all deployment types

Undeploy will only destroy the Module service if the Module is not in use by another deployment
When Module usage drops to zero, undeploy continues and removes the deployment from management
This approach would map cleanly - there is no cascading destroy effect. i.e. when you undeploy a jar that a webapp depends on
Services provided by the undeployed deployment would always go down, only classloader destruction is deferred