That was how Iris wanted respond. Truthfully, she didn't know all the details. That was sort of a blessing in doing Hera's work. It was hard to make an opinion on the matter of business she had to deliver if she didn't know everything about said matter of business. And if she didn't have all the information in which to make an opinion on the matter it was hard to refuse Hera on the basis of her personal ethics and even harder for others to chastise Iris for doing work that went against her personal ethics. Because there was little question that occasionally Hera asked things of her that probably went against the ethical system Iris had for herself.
She gave Hypnos a sleepy, half-shrug. It would be so nice if she could just sit. Her legs felt so tired. Iris bit back the tired sensation as much she could and answered him. “I can only tell you what I know, and that is very little. Alycone and her husband Ceyx referred to each other as Hera and Zeus, using the names sacrilegiously. This has angered Zeus who has punished him by casting a thunderbolt to Ceyx's ship at sea. He will not return to Alycone.” That was the simple and polite way of saying that Zeus effectually killed the man. Though why Hera wanted Alycone to find out in dreams was beyond Iris.
Iris would think if someone took her name sacrilegioiusly she'd want them to find out of their spouse's death in a more horrific way. Like seeing his body wash ashore or something and Iris was not a malicious goddess at all. But a goddess had to have some degree of respect from mortals.
“That's all I know, I'm afraid.” She yawned again.
In reaction to her yawn, Iris frowned. Maybe if she sat down for a moment she'd get some energy back. She looked briefly for the nearest bit of furniture in the dim temple. Maybe if she just... sat... for a minute.