It should be noted that this shows Cinebench IPC, not IPC in a general sense (which is almost impossible to calculate these days).
I'm still not sure about the whole binning situatio. I mean sure, server chips don't need to clock super high, they just need to remain energy efficient. However, we already know the top 5% bins become Threadripper chips so I am not convinced the cheaper desktop chips will boost to 5.1 GHz.
You're right, tho i do think its a pretty accurate overall representation, there is a video about somewhere, in it someone did a very detailed IPC comparison on all aspects of Ryzen + vs Skylake (Same as Coffeelake) and found they are pretty much identical across the board, but he also concluded Ryzen's IPC is heavily bottlenecked by a weak front end, i think we knew that, its why it responds so well to fast memory.
I would say Gaming is where its really all over the place, sometimes lower than Coffeelake IPC sometimes higher, depending on the game, for example Arma III in a single patch went from being typically AMD slow to getting a huge boost in performance equalling that of Coffeelake.
The thing is Arma III had never seen Ryzen, which is why it was patched.
I'll try and find the video, no promises its been a few months since i last knew where it was.
8400 boosts to 4Ghz.