There's a tier 3 support mastery called Arcane Celerity:

Arcane Celerity: Has a 30% chance of increasing the Turn Meter by 10% when a debuff cast by this Champion is removed or expires

If an enemy dies while it has a debuff on it, does that satisfy the condition for Arcane Celerity, or does it need to be specifically removed or expire?

Scenario: use a "target all enemies" type of debuff in Spider's Den, but the baby spiders might not live long enough for the buff to expire.

Same question applies to the Rapid Response mastery (but for allies).