There seems to be a lot of people fundamentally misunderstanding the source of this information. Claiming that the slides look "unprofessional and therefore fake" is a giveaway.
Tom's leaks come from anonymous sources and he is the one that compiled the information into the slides. These are not slide decks out of Nvidia; this is analysis and leaks that they don't want out yet. It's pretty funny how people call him an AMD shill even though he's very impressed with how Turing looks so far.
As for the comment about turing not aging well: It was a proof of concept for the RT cores, DLSS etc. They didn't have the formula figured out completely and you won't be able to use a lot of the features that even the xx60 series Ampere cards will. That doesn't mean those cards get slower all of a sudden, It just means they will start lagging in performance noticeably as new games take advantage of Ampere's significantly better RT performance. The performance won't scale linearly when comparing generations side by side.
The IPC gains aren't referring to Ray Tracing, that's overall performance improvement from uArch and process improvements.
For those of you that are genuinely interested I highly recommend you go watch the source video and not just an article reporting on it. If you want quality analysis and not just fanboy circle jerks, Moore's Law Is Dead is a fantastic channel.