A Wigwam for a Goose's Bridle

I’ve been thinking about story content recently. I have two questions/thoughts that are sort of related and I’d be interested to hear your views on the matter.

Firstly, trigger warnings.

If you’re at all active on the internet, you are probably familiar with the modern concept of trigger warning or content warning. This is controversial with some people believing it is unnecessary softness, but to those who have panic, anxiety or PTSD related to a certain issue, it can be incredibly helpful. Some people offer a trigger warning with a label e.g. this post discusses suicide. Some people won’t even read past the mention of a trigger warning, just in case.

I’ve read a few books recently that have blind-sided me with a traumatic event that you never would have guessed from the blurb/title/cover or even the first few pages. Topics have included death of a young child, severe child abuse,and one or two others.

Now I’m ok. These make me uncomfortable but not in a way I can’t handle. That said, in both of the examples mentioned above, if I had had an inkling that these were the topics, I would have chosen not to read those books, or perhaps at least not at a certain time in my life. I believe both examples could have been hinted at in the blurb without ruining the stories.

I’m curious to know from my readers, do you think some novels should come with content warnings, or if not warnings then at least make certain things clear from the start?

Related to this, how soon is too soon for a novelist to use an actual real life event in a book, with or without blurb mention?

I recently finished another novel which I won’t name so as not to spoil the story. At about 80% through the book, the disappearance of Malaysian Airlines flight 370 occurs. It is important to the plot. Characters have to deal with who may or may not be missing or dead. Further, it provides ideas as to what might have caused it. I did not see that coming. It just made me think, if I had actually lost someone on that flight, how would I feel to have the actual historical event mentioned in this book? Obviously people write about events within their lifetime often. There are books about 9/11, books about wars etc. It just makes me wonder, how soon is too soon, and should it be disclosed more obviously?