>>39565623BW also brought back Dawn so sinnoh canon to that series and from there you can work your way all the way back to kanto. XY is a direct continuation to unova so that makes kalos part of that continuity as well. You could say Alola exist in its own canon but misty and Brock exist and we see Ash's corphish which means his hoenn adventures also took place in SM's continuity.
TLDR: It's all fucking canon
