This also shows King Lear as a good example of why trigger warnings are unnecessary, given that in 400 years of performance no-one bothered with such warnings and no harm was caused by their absence.
Trigger warnings appeared because people were being harmed. They asked for a heads-up, so we gave it to them. It costs us nothing, except having to listen to the whining of ideologues who hate that we did something for somebody other than them.