It is true that Tage played center along the way including the time during which Granato was his coach. But that was 7 or so years ago. According to this article, Tage was switched to wing in college.
Tage speaks in this 10/12/21 interview from https://thehockeywriters.com/sabres-tage-thompson-moves-to-center/ :
I think Granato deserves credit for the switch
Tage speaks in this 10/12/21 interview from https://thehockeywriters.com/sabres-tage-thompson-moves-to-center/ :
Growing up, he always played as a center in junior hockey leagues until he switched to become a winger in college. Thompson expanded on this in his Oct. 4 media availability. “I was always a center, and then college was when I switched to wing. It’s been a while since I’ve played center, so as of right now, I’d say I probably prefer wing a little bit better, but I’m excited about the opportunity.”
If the esteemed posters above are implying that it was a no brainer that Tage be tried at center, I think that is a stretch. It's been 7 years since he played the position and that was at an entirely different level of hockey.
I think Granato deserves credit for the switch