I agree with your point about fostering confusion. I've read the book Anon describes and found it to be a biography of someone known as Swami Satyananda, a boyhood friend of Yogananda's who PY describes as his "disciple" in the first edition of the AY.
The author of the book is Swami Satyeswarananda, a disciple of Satyananda's from India. He is a former student at the Ranchi school, a former lawyer, and someone who claims to have been sent to the West to bring the "original" kriya techniques by Babaji; claiming that PY "modified" them for the soft westerners.
After reading the book it seemed to me to be a sort of grudge-settling thing between what Satyeswananda belives PY did to his guru. It seems to have something to do with the Ranchi school. Apparently for a time Satyananda was the headmaster of the school and wasn't pleased when PY returned to India in 1936, thereafter replacing Satyananda with someone else.
Satyeswarananda makes the claim, as both PY and Satyananda were disciples of Sri Yukteswarji, that PY was the leader-disciple for the west, and Satyananda the leader-disciple for the east. Whether this is true I'm not sure, as SRF has made it clear in their history of PY that he was Sri Yukteswarji's chief disciple, without any distinction between east and west; also they make no mention of Satyananda anywhere in their writings.
To me it seems that there continues to be grudge against Yoganandaji by this fellow Satyeswarnanda; and if he can do something to even that score he will do so, as this book (and its new edition) seem to confirm.
You might want to get a copy and check it out for yourself. There's a lot about PY in the book, but it's definitely not in the same respectful, devotional, form that one's used to reading.