Are the final events of DBZ considered canon?
In Dragon Ball Super , Dende makes a mention to Uub and he tells Goku it would be good he trains him. That's meant to connect Dragon Ball Super with the end of Dragon Ball Z. And as for Trunks and Goten appearance, in Dragon Ball, 4 years passes between Goku meeting Bulma and killing King Piccolo, and his appearance (which is almost identical to Goten by the way) doesnt change. So yes, the final events of Dragon Ball Z are canon.