A customer experienced a traffic blackhole when a storm-control action-shutdown was triggered. It was triggered on the MC-AE interface went down, but its child interfaces remained alive and the LACP state stayed in CURRENT, causing the remote peer to keep sending traffic to that interface. 

It has been confirmed to be an expected behavior, and to avoid the symptom, "set switch-options interface-shutdown-action hard-shutdown" needs to be configured.

A customer experienced a traffic blackhole when a storm-control action-shutdown was triggered. It was triggered on the MC-AE interface went down, but its child interfaces remained alive and the LACP state stayed in CURRENT, causing the remote peer to keep sending traffic to that interface. 

This is an expected behavior. 
By default, strom-control action-shutdown is in soft-shutdown mode and will block the data traffic, but not the control traffic. 
To bring down the physical interface, hard-shutdown must be configured as below:

set switch-options interface-shutdown-action hard-shutdown

Initial Version

https://www.juniper.net/documentation/us/en/software/junos/security-services/topics/ref/statement/interface-shutdown-action-edit-switch-options.html