Does Sasuke really need a new arm? So we all know that Sasuke does not have an arm. And after his fight, Sakura was saying something about making an arm out of Hashirama's cells. Thing is—Sasuke has the Rinnegan, and knows how to use it. So, he can use the Asura Path technique to get a new arm. So what was the need for an arm made of Hashirama's cells anyway? Why did they make one for Sasuke if he can get a new arm himself? And why is Sasuke missing an arm in the first place? He should have had his own new arm by now.
I think it's because sasuke lost a lot of his powers after he sealed kaguya. (Naruto even list his SOSP (sage of six paths) more).
Sasuke only had his rinnegan, ad so, I don't think he can restore his arm using asura path technique