I've been going thru the updated lore of Taric, Pantheon and Diana. I think the next event will have to do with The void. In the lore there are quotes of the void for example in Tarics lore it says,
As the Protector's whispers faded, Taric received a final warning: He would stand as the Shield of Valoran, but crashing against him would be a wave of howling madness, an ocean of gnashing teeth intent on consuming all, a squalid horror born of the Void. Also Dianas lore says,
Its crumbling walls were painted in faded frescoes depicting warriors of silver and gold fighting back to back against an unending host of grotesque monsters as the sky rained comets of searing light. Lastley Pantheons lore says
Pantheon’s latest appearance has been greatly debated by the elders of the Solari, for his arrival is both a blessing and a curse, as it often heralds a time of darkness yet to come. So with these In the lore it only makes sense that The Void is the next story to touch upon.