"...their angry reactions to it floored me"
I think the idea of there being such different reactions to a relatively recent film by different generations is interesting but I am not sure it is as clear cut as the article. Of the 3 specific reactions, here I am with, and was with Gen Z on the first. I am partly with them on 2, more because I thought it was part of a mawkish manipulation in the film whose structure has always seemed a bit off. 3, not sure. I would have to watch the film again as I haven't seen it since it was released, in the main because of 1 and 2.
In the theory of the 'generations', I should fir full disclosure, admit that I am on the Baby Boomer/Gen X cusp and 'officially' a Boomer. I wonder that makes some difference
https://www.upworthy.com/my-gen-z-kids-reaction-to-dead-poets-society-ex1