The answer is the same as before.
Nah, never, nada, no way, is just Naruto having a brain fart and making absolutely no sense.
Granted, if can lean into the idea of just scaling him up and not scaling anyone to him, but I am vehemently against this. This is no different from Gamabunta not getting one shot to Oblivion by Shukaku, inconsistency.
And as for what I mean, let me put it this way... Zabuza never says anything even similar to "he was holding back" but that he is pained fighting them and Sasuke directly says no to Sakura's "you evaded any blows to critical areas!" comment. So what makes sense:
A) Haku was never going all out, prolonging the fight with Sasuke and draining his reserves despite the fact Zabuza was also in danger fighting Kakashi.
B) He never even held back, but rather never tried any lethal attack (we literally see Haku is accurate enough to put someone in a death like state with even a Jonin non the wiser people, come on) by "holding back" and never from the start planning to give any killing blow. Hence Sasuke barely incurring any actual damage but still looking dead like Zabuza, except that would have never happened had Haku not forced him not to evade by attacking Naruto and the fact he needed his mirrors to even intercept Kakashi, the dude he could totally beat according to Zabuza.
Why does holding back implicate using less power, when we have seen Haku can easily make you pass out or outright kill you, and the only holding back he could have done in the dome was missing Sasuke's vitals? You could easily take Sasuke's statement as "from the start he wasn't trying to kill me", which makes more sense he was trying to injure him enough to put him out of commission or land a nice blow with a needle to get him out of the fight since, as Zabuza put it, "fighting you kids pained him". The only things against this are two statements from Zabuza that are never proven right, and the War Arc which is much, much easier to call a plain inconsistency. Even his "jutsu" being better is a terrible piece of proof when this was when Kekkei Genkai were treated like the jackpot of a Lottery.