Does anyone know if they upgraded the 2004 alternator to a new one? And if so, what are the changes?

They recently changed my alternator/battery under warranty and happened to solve an issue I had where my manual 2004 8 started to buck and shake at 5k+ rpm only when the AC was on. I'm trying to figure out if this is coincidence or the actual fix as my car is going off warranty really soon. Tks

 

if you had a bad alternator even replacing with a 2004 one should have fixed the issue shouldnt it?