I didn't know about the callous- that's definitely bad news. Another singer that I like, James LaBrie of Dream Theater, had a vocal chord rupture that in the mid 90s and his voice wasn't 100% until around 2004-5.
But if Scott thinks he's singing better than 10 years ago, he's delusional. Just listen to the chorus.
http://www.youtube.com/watch?v=tfL4BSDqPt8
http://www.youtube.com/watch?v=aHQ1yazkwnI
Otherwise, crappy interview. Scott repeating talking points clearly handed down from the label and suggesting that Mark can't compete creatively with them when they're together = lame.