There are some that argue Mozart was a punk because in a lot of ways he embodied it's spirit as going against the popular grain at the time. I mean he now has an entire Wikipedia page dedicated to his love of scatological humour.
https://en.wikipedia.org/wiki/Mozart_and_scatologyThat's pretty punk. It's definitely more a state of mind for me and in that way the music isn't so much the main point of it.
I think if Britain had a punk revival it would be almost exactly the same topics for the songs as it was the first time round. The current Tories idolise Thatcher and seem pretty committed to continuing her ideas. The rich getting richer, the poor getting poorer, inequality, homelessness, unemployment, classism. The recent trend of looking back to the 80s for politics, fashion and media (Stranger Things anyone?) has been very strong and I'm kind of surprised the music hasn't come back with it. Like I said, it's the perfect breeding ground for punk right now. Politicians are feeling more remote than ever despite social media and there is a sort of hopelessness creeping in generally in a lot of areas of society which will either lead to people completely giving up or getting really pissed off. Judging by how common protests and counter protests are getting, it should be only a matter of time until Johnny Rotten 2.0 pops up.