My Prediction:
PS5 announced at Sony's event mid 2020. Releases early/mid 2021.
Sony won't take a year between announcement and release. Too long to keep up the hype, too many chances for a competitor to steal the thunder with a super early announcement. They probably won't take even as long as it took between PS4 announcement and release. If they announce it just before E3 2020, expect it to be out by Fall 2020.
The X1X (and the PS4Pro, for that matter) are completely immaterial to what Sony is going to do. They're just premium products that have a negligible impact on the market. They're going to release their next console when they have the tech to do so at a reasonable price, not earlier, not later.
So correct me if I'm wrong. But from what I understand it seems that even next gen will be a bigger leap than ps3 was to ps4? Even with conservative/realistic assumptions? I mean as a whole package, I don't mean in terraflop terms
Really hard to say. It will be a larger jump in some aspects, probably - likely a much more performant CPU, for instance. GPU- and memory-wise, the leap from PS3 to PS4 was gargantuan in more ways than just performance, but also tech architecture, so that would be a hard one to surpass. All in all, I'd say that it will probably be in line with what we had before.
That's a fluff article if I ever saw one.