What to know before Krakoa?

I've given myself the task to catch up now that I'm on a break with X-Men history, I started with Morrisons New X-Men, then into wheedons Astonishing, etc etc, saw the whole Mutant Messiah trilogy, Schism, Uncanny by Gillen, AvX, All new and Uncanny by Bendis and just today I reached issue 600 just before Secret Wars.

I've been reading that the X Titles were in somewhat of a weird place from 2015-2019 and they had some shenanigans with the Inhumans that I don't really give a crap about because I don't care about the inhumans at all.

I read X Death (Cyclops dying) and I think that's as far as I got, I saw a guide saying that then it came to Uncanny (2016) and then Uncanny (2018), that along the way Jean came back (my poor girl Emma is gonna get sidelined, I guess it was good for the 10 years it lasted), that the time traveling X-Men returned to their respective time and that Xavier not only came back to life but also got a walking body(?). Some titles like X-Men gold, blue and red sprung too... all I'm asking is how critical it is to read all that before Krakoa as I've seen opinions on that period be somewhat neutral leaning to negative, I'd like to read the conclusion to the displaced OG 5 but I don't really want to chump another 20/30 issue series for it, same for Jeans return, if Hickman explains that in his Krakoa era even briefly I'm settled.

So then, what should I know, in detail, before heading into Krakoa? Unless I should actually read all the 2016-2019 titles. Thanks!