Are the rules of POV changing?

The rules about point-of-view are handed down from old writers to new ones much in the way parents teach their children to play catch or ride a bike. To sum:

First person, or “I” – the narrator is the main character and knows only what she sees or has been told.
Second person, or “you” – usually only seen in “Choose Your Own Adventure” books.
Third person, or “she” – The narrator knows all, but limits point of view to a few main characters to keep things from getting confusing. Almost always, these characters and their points of view are introduced in the beginning quarter of the book, so the reader knows whose story it is.

These rules are pretty much sacrosanct, and to violate them means incurring the wrath of anyone who has ever taken a creative writing course.

This past week, however, I read two traditionally published books that ignored the rules. The first, Sophie Hannah’s The Monogram Murders, is a mystery starring Agatha Christie’s most famous Belgian detective, Hercule Poirot. But Poirot is not the narrator – the book is told in first person from the point of view of Detective Catchpool, a hapless detective from Scotland Yard who pretty much needs Poirot to tell him how to tie his shoes. This is odd because Catchpool must have ESP, as he describes many scenes in which he is not present. Poirot will be having a detailed conversation with a witness, and several paragraphs or pages later, Catchpool will join him at the coffee shop or mention he’s someplace else entirely. Monogram has received mixed reviews, but a lot of fanfare since it’s an authorized Poirot tale told by a famous mystery writer using Christie’s style. Nevertheless, Christie was well versed with the rules of POV, which she exploited to great effect with her debut mystery, The Murder of Roger Ackroyd.

My library finally coughed up a copy of Jojo Moyes’ After You, the sequel to her blockbuster Me Before You. Moyes is a very talented writer who has used first person, third person, and multiple narrative threads in her earlier novels, but this book is the first time I have seen her break a rule. After You is Louisa’s first person account, and in most of the book she’s preoccupied with a teenage girl named Lily. In the last third of the novel, Lily goes missing, and Moyes jettisons her narrative structure of first person, past tense to spend several pages in Lily’s third person, present tense world. Once this plot twist is resolved, Moyes returns to Louisa’s first person point of view.

It’s been said that a writer has to know the rules in order to break the rules, but I found these rule-breakings jarring. In both cases, they pulled me completely out of the story and left me mumbling about “whose story is it anyway.”

But perhaps I’m being an old stick-in-the-mud. Are writers, editors and publishers becoming more lenient about the rules around point of view? Should I expect to read more examples like the two above? Or did I just happen to catch two exceptions to rules that are still alive, well and kicking?