Just because a major conflict has ended, does not mean the end of the series. Note one is that Izuku still has embers left. And without All for One, he shouldn't be running out anytime soon. Like all might still have a lot of power left, and only burned out as fast as he did due to Kamino. So if used strategically the embers should last a while. Additionally, any major series being run in SHonen Jump gets a two to three-week warning period before it finally ends. which we have yet to get. So I'm thinking we might just get through highschool with the gang before it officially ends.