Edmonton Oilers lose Patrick Maroon? Just how many top wingers can they let go?

Is Patrick Maroon the next top Edmonton Oilers winger to leave town? And if he does go, what then? Maroon has been the Oil’s best and most consistent pure winger for two years now.
If he goes — and it’s looking like he will — Edmonton’s already thin group of wingers will look intolerably skinny heading into 2018-19. How did it get this way? 
In 2015-16, Taylor Hall was the Oil’s best winger, while Nail Yakupov and Teddy Purcell were third-line winger