As taken from Wikipedia:
Wally is currently planned to appear within some episodes of the five-episodic Monkey Island saga known to be the sequel of EMI. Though it is unclear which role would be attributed to him in Tales, Wally is supposed to be a helping character who would aid Guybrush and also become a member of his yet another crew to set sail to Monkey Island.
I know that the general norm is not take Wikipedia for serious... Hmmm, or is it true?! ;) Dunno. What do you guys think?