Well, honestly, I don’t think we can know that much for certain about what the Buddha’s awakening consisted in. We have various texts, which seem to date from the time of the Buddha and which have an overall circumstantial and narrative coherence that suggests many of them originated at about the same time, and within the circle of the Buddha’s followers. But it is hard to discern which of them record the Buddha’s own words fully accurately, and which of them are only the fallible recollections of hearers later reporting what they thought the Buddha said. Those recollections will be colored by the personal limitations of the hearers, as well as their own preconceptions about the world.
More importantly, even when words are recorded accurately, we can’t know for sure what sense the Buddha intended to give to those words, when he was speaking figuratively and when literally, and why the Buddha was giving a teaching consisting of those very words to any specific hearers who reported it later. Some of what we have, then, might amount to no more than instructive fairy tales the Buddha presented to help guide people he regarded as having childlike minds. I think the suttas present us with a complex literary and detective story, and understanding what the Teacher was actually up to and really trying to communicate requires a long process of creative and probing reading, as well as experience with the practice. Even then, we might not be able to get it entirely.
But it is also important to distinguish what the Buddha’s awakening actually consisted in, from what the Buddha, or others, might have thought it consisted it. The Buddha’s views were just as much conditioned as anyone else’s. We don’t need to assume the Buddha was omniscient or incapable of error, even after his final liberation. But if we have faith in the reality of that final liberation, we do have to conclude that any such errors or lack of knowledge were not of a nature to cause him further suffering.
My understanding of the nature of the goal is captured by the formula, “This is peace, this is exquisite — the resolution of all fabrications, the relinquishment of all acquisitions, the ending of craving; dispassion; cessation; Nibbana.” The person who has achieved that state has “laid down the burden” and “utterly destroyed the fetters of existence.” It is all about what states of mind we can succeed in bringing to an end, not what positive states of belief we acquire.
I don’t see any reason to think that the attainment of such a liberated state, and the ability to teach the path to its attainment, would require any comprehensive understanding of the entire nature of existence, or a view into the future and past of other living beings as they move in and out of the various “mansions” of the universe . Indeed, these things strike me as quite irrelevant, and the aspiration to achieve this kind of “superknowledge” is more likely to be a cause of suffering than to be part of the path to ending it.
If the texts contained any actual arguments for rebirth, or serious forms of evidence for rebirth, that would be something to take into account. But no such arguments are actually presented. Instead the texts only seem to present us with various individuals who share a conviction that rebirth of some kind is real.
I prefer to believe that the Buddha was an ordinary, mortal human being, with a finite mind and finite cognitive capacities, who achieved an extraordinary level of mental purification and relinquishment leading to the cessation of suffering. After achieving this state, the Buddha attempted to describe its experienced character as best he could, and teach others how to attain the same state. It seems to me much more important to pay attention to what the Buddha taught about how to achieve release or liberation than any views he might or might not have held about the fundamental nature of the universe. Nor does it seem plausible that a finite human being could ever know the fundamental nature of the universe in any complete way.
The subsequent Buddhist tradition has been bedeviled by a Faustian impulse - philosophers and siddhas of all ages driven by an intense cravings for cognitive attainments and powers, and for the possession of answers to all of their many metaphysical questions. But these cravings are themselves a major source of suffering. The path that I understand is all about relinquishment, not attainment. So I have worked on the assumption that if I were ever fortunate enough to achieve the full liberation of nibbana, I probably wouldn’t know any more than I do now about why there is a universe, why it works the way it does, or even what is the ultimate ground of my own mind and its possible states - including the liberated state. I would just be in the liberated state, which need not include a full and complete understanding of the nature of the state one is in.
Probably the greatest source of human suffering is the grief we feel over our ongoing loss of our past states of being, and the anguish over our own impending mortality, an anguish which is grounded in the brute animal craving to survive and continue. I view the goal as one of liberating myself from this grief and painful craving for future existence, not attempting to gratify the craving by convincing myself that I will survive beyond my mortal limits.