I agree with the idea of a warning at the time of ticket sales. It’s a good idea. I do agree with the other poster who thought that it should only apply to excessive political commentary. For instance, last year I saw a solo Rick Wakeman show in which he performed songs interspersed with amusing stories, which is what it was supposed to be, and it was great. No polarizing political commentary.
I will be seeing Graham Nash later this month, and that is supposed to be the same thing.