Givi, thank you for your explanation about the difference between the teaching in the first book and the last one(s). I will share a guess about it.
First of all, as you can also agree, Maharaj’s teaching by itself is not enough to deal with our life. That’s why, I think, people like you and I are interested in the Cassiopaean experiment, among others. His teaching can be beneficial from certain aspects but eventually it’s kind of an “escape” teaching. Or rather, from STS to STO through the shortest way (fastest awakening) possible; like the C’s reference to the “Ruby slippers”. Whoever can leave the STS realm so easily, I congratulate them, but I think we, like a great majority of people, are inclined or hardwired to embrace our life as “our life”, not completely as a nightmare to be awakened from or a prison to be escaped. I think this might also be related to the C’s remark, “All who have fallen must learn ‘the hard way.’” Shortcutting is not often a viable option. But still, such teachings can be beneficial to some extent.
As for the difference between the first and late books, I remember, a few years ago, trying to read some of his later pieces but not getting the same taste as from the first. I can’t exactly remember why I couldn’t continue reading those, but I probably thought the later books could be beyond my comprehension, that maybe I haven’t finished my work with the first book yet.
But now I think the difference might be related to Maharaj’s retiring from life, getting close to death. I will try to explain this possibility.
I think that the examples you provided about the “great difference” are not enough to claim a radical change in the teaching. For instance, Maharaj already mentioned the transitory nature of “I am” consciousness in the first book, too.
When pure awareness is attained, no need exists any more, not even for ‘I am’, which is but a useful pointer, a direction-indicator towards the Absolute. The awareness ‘I am’ then easily ceases. What prevails is that which cannot be described, that which is beyond words. It is this ‘state’ which is most real, a state of pure potentiality, which is prior to everything.
One thing is certain: the real is not imaginary, it is not a product of the mind. Even the sense ‘I am’ is not continuous, though it is a useful pointer; it shows where to seek, but not what to seek..
The same applies to your examples of “…that no one lives in a body, no one is alive..” These are already among the main themes of the first book. I can’t remember anything specific from his latest books but if you can give more concrete examples about any radical difference between the first and latest books, we can examine them and try to make a conclusion. I can be mistaken.
So, this is my guess: Obviously, at the time of the first book, Maharaj was relatively younger and inevitably more involved in “ordinary” life. As far as I remember, he tells or implies in “I Am That” that he hadn’t planned to be a public speaker or teacher. He was a very ordinary man operating a shop, selling tobacco and other items. But upon “awakening” after three years of meditation on the idea “I am the Supreme”, which his guru had suggested him merely to focus on, he gradually became a guru himself. And then he had to serve by answering innumerable questions by endless swarms of visitors.
I think he saw the relative ineffectiveness of his teaching or suggestions about "awakening in the shortest way possible". And probably, he was also subjected to a lot of psychic attacks from Lizzies, etc. because he was not a fraud. He dispensed a lot of true knowledge and influenced so many people. I think his death from throat cancer is somehow related to this “tiredness of speaking”, possible psychic attacks, and his need to die and rest. And the differential theme, as you imply, in the final books can be related to this situation. In his younger period, he was relatively more involved in the issues / questions associated with people’s ordinary life. But close to his death, his limited interest in the mundane was also lost. His greater or sole emphasis on the "absolute" was what he personally “needed” to concentrate on then.