Concussion missiles use this wording and I believe that I saw it at least one other place too.
Pp. 5 & 13 of the 2e rules reference define what it means to “hit” with an attack by having uncancelled (BOOM) or (KABOOM) results at the end of Attack step 4. I assumed that “after this attack hits” means the effect triggers directly at the end of this step before damage from the uncancelled (BOOM) or (KABOOM) results is applied in Attack step 5: Deal Damage. Others disagree with my interpretation. Although several other wordings are called out triggering in a specific order in Attack step 8: Aftermath, this wording is not...which strengthens my belief in my conclusion
The timing of this trigger changes CM effectiveness in a big way.