Jhin is on the loose and in his release cinematic, we know he would like too assassinate Vi. Assassinating a famous police enforcer could distabilize Piltover and would be good for Zaun's illegal activities, therefore Camille, with her connections whats to stop Jhin before he does anything. This is happening on the present. Around 70% that it could be canon.
Riven comes from Noxus but we don't know much about her origins. She may have had prove her strength in the fight against Draven and that's why she became a general later on. This of course, happened in the past, before the Ionia invasion. This happened in the past. Around 85% that it could be canon.
While we don't know when was Sion ressurected, it may have been very well around the Ionia invasion. We know that most Ionia champions participated in war in a form or another, with Irelia probably being the most important figure here. This could have also been the moment where Yasuo leaves his post to help out some Ionians, getting the people he was supposed to protect killed. Shen is missing but he could have very well been fighting in another front. (Personally, I would have prefered that it would be Shen shielding and teleporting to Irelia, bringing his ninja friends sou we could see the Kinkou thogether. Also, both Irelia and Karma dislike each other stances on the war, so it's weird seeing Karma helping Irelia. Not that she wouldn't help a fellow ionian in need but still, weird choice.) This also happens before Akali leaving the Kinkou. This, of course, happened in the recent past. Around 99% of being canon.