WieWaldi I'm not familiar enough with JW's music to have a strong opinion, but my question is, stylistically, is it different enough from what's generally called classical music to warrant it being called post classical. Based on the pieces I'm remembering, I would just call that classical, but maybe I'm not thinking of the right thing.
A good addition to this discussion is Billy Joel's classical compositions "Fantasies and Delusions," here's a sample:
Stylistically, I would call this classical. I don't care that they were written in the 21st century, if you compare those pieces to Einaudi or George Winston (both of whom I want to call post classical), the stylistic difference is quite stark.