It sounds better than it did 5-6 years ago, sure. But before that? Nah. He sounds great for his age. His voice still cracks or goes flat, and there are plenty of mistakes etc.
To me he just sounds "right" at the moment. He's singing well, but his voice is showing its age. He's definitely not sounding better than he did decades ago. And that's fine, the shows are great, and the band are heavy as fuck. Can't wait to see them again next week.
I am certainly willing to believe some technological enhancement has been used on his hair though.