Yes, he did destroy his voice with AC/DC.
The famous “voice cracks” started during the NA shows, and you can literally hear them. The very very high parts he was going with rasp, such as Hells Bells or Shoot to Thrill. You can go and watch the videos, it’s all there.
This same songs, during the Europe run (that came first), didn’t have any voice cracks. It was literally the first time we ever heard Axl’s voice crack and it’s all in video, after that everything went downhill.
I do agree with your post, though. But I don’t agree that the shows with AC/DC “didn’t damage his voice”. It’s where all started! It definitely deteriorated his voice faster than If he hadn’t played those shows.
Ultimately, the rest between SA 2016 and Asia 2017 is what killed his voice for good, IMO. Those shows were absolutely horrendous, and he clearly didn’t sign or even prepare during those months.