The problem is that Foegele is playing on a $2.75m AAV contract right now, and becomes a UFA at season's end. The question now is, how much of a raise is he due for? NHL salaries are not often something that can be easily predicted, and some team (Oilers included) could ultimately be a sucker and pay way too much for a player after a career year.
However, Foegele is perfect for the Oilers' playoff push this season. He is a value winger that can play on the second line, and can complement the game of Draisaitl well while also being responsible defensively. There is a long regular season left to see if he keeps it up, and then speculation about his next contract can begin.