Yes, I read
I, Me, Mine years ago and skimmed through it in about an hour (I skipped most of the song notes). I picked it up again a couple of months ago because I wanted to know what George had said (or specifically, omitted) that had irritated John.
"Well, I was hurt by George's book, 'I, Me, Mine' ...so this message will go to him. He put a book out privately on his life that, by glaring omission, says that my influence on his life is absolutely zilch and nil. In his book, which is purportedly this clarity of vision of his influence on each song he wrote, he remembers every two-bit sax player or guitarist he met in subsequent years. I'm not in the book."
So I read it, specifically looking for these sax players and guitarists. I don't recall George listing even one sax player-- did I miss it? The only guitarist I remember (apart from the other Beatles) is Clapton, mentioned in George's notes about his cowrite with him on "Badge". Ringo gets a credit in this entry as well, for contributing the "swans who live in the park" line, but I think mostly because George thought it was a funny story that Ringo should show up drunk and spout this line, and because Ringo doesn't exactly have a heaping pile of lyric credits. George's mom gets a credit for one line in Piggies, the one about the "damn good whacking." Considering all the trouble this line caused, George should have left Mom out of it.
I apologize, once again, for not having the book in front of me (it's back in the library). So I'm going from memory. Still, I didn't really find any evidence for John being slighted in favor of other players; people are mentioned in the most offhand manner possible. You really need to know George's life history before reading this to follow it. IMHO, the real people who should feel slighted are George's wives. They hardly get a mention either, except in passing. He certainly never describes meeting them, or when he's married, or when he's not, just one allusion to his "naughty period" and then Olivia's name drops in for some other song notes.
I think the problem is that this book is not really an autobiography. It's more of a memoir, a collection of extremely random remarks by George. Derek Taylor, who ghosted it, says that most of George's recollections involved various models of cars he'd owned (not even guitars!)-- but out of mercy to the public, Taylor axed most of these. If the book had been titled "George's stream of consciousness about some people he knew but he won't tell you who any of them are and random song notes", it might have set the public's (and John's) expectations a little closer to the reality. Kaleidoscope_Eyes, does this match your impression?
Regarding John's hurt feelings, George did mention in one interview that John was annoyed that George didn't credit him with John's 1-line contribution to Taxman. You can hear George speak for himself here:
The sad part is that George called John to talk this over, but John was out and never called him back. And then John was gone.