Oh, I can see how you can think that.
It’s just alluding to the fact that the speech bubbles position next to a character doesn’t really determine who is talking. That’s why even when some speech bubbles are next to a character, they still have the bubble pointed towards them.
If Oda wanted to make it look as if Zoro was asking that, he would have drawn the arrow pointed towards him but he didn’t. Even though in later panels when he wants to make it clear Zoro said something, he draws those exact arrows pointing towards him.