I'm a fan of Graham Hancock but I understand people here might be sceptical (so am I). Watching a national geographic documentary and seeing the structures raises so many questions though...
I have no doubt these constructions were possible With stone age tools but where did the knowledge come from? Before agriculture and a written language it seems impossible to maintain such advanced knowledge over many generations.
Does this push back the date of civilization at all? I can find plenty of people poopooing the idea that it wasn't built by cavemen. I can't find a legitimate source for an alternative timeline.
It seems like devolution from the earliest dates we have. Knowing there was a cataclysm that ended the last ice age around the time of Göbekli Tepe, why would they have intentionally buried it after that date?
So many mysteries, so few sources...
If you are genuinely interested in the epipaleolithic/pre-pottery neolithic transition and the ancient near east, you might want to start with Ancient Turkey, by A. G. Sagona and Paul E. Zimansky, 2009. Of interest might also be J. Cauvin's 2001 The birth of the gods and the beginning of agriculture. More specific to the Natufian culture, you might want to have a look at the various books and articles by Ofer Bar-Yosef. For Gobekli Tepe specifically, the primary reports are by Klaus Schmidt, though his focus on the single site might be less helpful if you are looking for contextualisation. To understand Gobekli Tepe it is also fundamental to look at Nevali Cori (excavated by Harald Hauptmann). This site is more 'complete' in its assemblage, though less famous. Have fun exploring, the earliest neolithic is a fascinating period.
Gobekli Tepe comes up a lot here because it's popular with both the fringe archaeology (Hancock etc.) and pop archaeology crowds. But they both really, really over-hype it.
The site dates to the early Neolithic, so the people who built it were not "cavemen", they were early farmers in exactly the period where we expect to see increasing social complexity. But people have a tendency to conflate "impressive" with "advanced". Sure, Gobekli is incredibly impressive, but does it really take a "civilization" to make a few standing stones? All Gobekli Tepe actually is, underneath the hype, is a modestly sized ritual structure – or maybe just a well-decorated hamlet. It didn't take huge amounts of labour, specialised knowledge or advanced technology to build. If anything, what's interesting about Gobekli is that people wanted to build it, not that they could. But again, this exactly the kind of experimentation with new social forms that archaeologists expect to see at this time, so it doesn't "push back" anything.
I'm not sure where you got the idea that the last Ice Age ended with a "cataclysm". It didn't end with anything particularly noticeable to the people living through it. The weather just changed a bit. Similarly, I don't know what you mean when you talk about "devolution". Although Gobekli was an early one, many similar complexes are known from the region and they gradually increased in scale over the next few thousand years.