Institute of War??? (Canonicity of JoJ, Summoners, etc.)

I'll start off by stating that I am a HUGE lore fanatic. League's lore has some of my favorite story telling and lots of characters and locales that I can really sink my teeth into. The biggest problem though, and I've seen others address it too, is that while League has this vast universe and complex lore for every character, it lacks an overarching story. Long ago, before my time in LoL, there existed the JoJ. But then the Riot nation attacked, and rebooted the lore, or so many people claim. As I spent multiple hours diving into old lore and trying to find parallels and connections to the new lore I found nothing on the new lore direction. Now, this doesn't mean it doesn't exist, but if nothing else it is difficult to find and overall confusing as no one truly knows what is canon and what isn't. So I will now propose my questions after such a long introduction. What remains of the old lore? Do Summoners and the Institute of War still exist? Why do the champions fight on the rift? Is the rift still a Field of Justice? What do they get out of it? I love Riot, and this isn't an attack or defacing. I'm simply needing clarification or {{summoner:2}} (ba dum tss) on the future of the Lore. Most lovingly, Shivv