Certainly, not every reply needs to be a rebuttal. But it usually is, here.
On the other hand, if you’re going to rebut, and you think the other party is trying to argue honestly, your lower bound really should be around DH4 (counterargument) in a setting with many speakers. In a private setting, simply disagreeing (DH3) can be useful to just explain internal state. “I disagree with X, but I’m not sure why. Hm...” But it’s logically rude to state simple disagreement as if it were an actual argument. :)
Certainly, not every reply needs to be a rebuttal. But it usually is, here.
On the other hand, if you’re going to rebut, and you think the other party is trying to argue honestly, your lower bound really should be around DH4 (counterargument) in a setting with many speakers. In a private setting, simply disagreeing (DH3) can be useful to just explain internal state. “I disagree with X, but I’m not sure why. Hm...” But it’s logically rude to state simple disagreement as if it were an actual argument. :)