Two things made me think about this:
It would fit still with the lore retcon (somewhat) especially if you removed the Kalamandra storyline because of how involved it is with the old League.
I'm grasping at straws here, but in (get ready for THIS refrerence) Blitzcrank's Poro Roundup Veigar flys in on balloons for his bossfight which is reffering to something in the JoJ.
Originally it was said that you can basically leave out every mention of the league and that as long nothing new contradicts the old,the old is still canon.
However the retcons made clear that pretty much everything old can be retconned,regardless if it fits with the new lore or not.It doesn't have to be retconned,but it still can be retconned.
The noxus invasion in ionia still happened though and the same seems to go for the capture of J4(why else would leblanc have Jarvans blood?).The Sion promo also mentions a charade involving J4s blood,implying that even kalamanda is still canon to some extent.
Honestly the only way for Riot to clean this up is to scrape everything and rebuild the whole thing. Not try to spot check it here or there. That's why I gave up on the lore and just play now. :(
No, because the league of legends essentially never existed with the new lore, and all lore before the retcon as well.
Nothing lorewise changed since the lore retcon was announced (excluding lore pertaining only to new champions)
A lot of the JoJ (with the exception of Kalamanda and the IoW) generally just had to do with events or stories going on. Like the interview with Mordekaiser over the creation of the Pentakill band is probably still canon, but being a metal band, they had to make some crazy story (see the Pentakill story on the lolwiki, it's completely over the top and crazy) or like how Akali and Shen do the Blood Moon event, reenacting Reina's encounter with the demon(oni). Those are probably still canon, but one of the fights between Malzahar and Kassadin (it involves a nexus and Karthus) probably isn't or the Kalamanda events, or of the like, if the IoW was involved, it probably isn't canon. But the interviews, the fun stories like Blitzcrank's Dating Services, probably are.
