Originally Posted by
Shurrikhan
Technically, it wasn't just the functionality that was changed. Interrupts only stop an ongoing cast. Silence also delayed future casts, albeit only for a single second. This actually made SCH's AoE silence (via Selene) pretty damn strong for gathering casters in certain dungeons, in ways a mere interrupt would not have done.
I imagine the change had more to do with future-proofing potential problems with affectable boss's skill scheduling than that, though. Since when has XIV ever given a damn about dungeons, after all, save to make them more shallow?