Blizzard isn’t going to be inclined to give Priests an interrupt because Disc somehow keeps managing to climb its way into FOTM status despite not having an interrupt.
When you bring a Prot Paladin they more then make up for any lack of interrupts brought by other specs.
Should priests have an interrupt? No. That isn’t our problem. In delves, we have other cc and a stun. I’ve had no problem doing delves as holy by myself up to 10 so if I can do it, anyone can. Interrupt not needed. Plus, as another poster said, we will become the ones expected to handle interrupts.
I think the only time I have been irritated at not having a proper interrupt is the murloc special duo boss. That murloc casts a heal that scream and chastise doesn’t interrupt. Maybe censure does though? Haven’t talented into it to see.