Hello,
I just had this happen to me. I had a 10/16 starship launched. The opponent used a Spell to make it dormant (seemed like the spell was used twice even though cast once, but that’s another issue…). it was dormant for 2 turns then came back. it was killed via a minor attacking it. It had several deathrattles, including dealing damage equal to the minions attack to up to 2 enemy minions, but nothing happened except it dying.
This happened in the arena and would have swung the board state back into my favor, but again nothing happened with the deathrattles.