I feel like Zoro was using Haki against Daz Bones, but Oda just hadn’t really figured out what Haki was (and kind of still hasn’t to this day) yet.
It’s obvious that Haki was always planned to be a thing, the Shanks vs Sea King thing is proof of that and if you watch the Live Action, which Oda is super involved in, they make it super clear for manga readers that Shanks used Haki there.
Telling what is and isn’t Haki for pretimeskip stuff just gets a bit complicated, because Oda hadn’t decided to make it easier for us by just adding black for all Haki attacks. I remember Garp smacking Luffy around at least once or twice and Luffy being confused about why it hurt even though he’s rubber. (Doing my very best to not go into a rant about why Garp utterly failed when training Luffy as a kid by not telling him anything about Haki, even though he knows it’s literally the most important skill anyone can have.)