Anything is possible but not probable. In WIlls character will definitely changed but in a negative way like savvysparrow mentioned. His jelousy will blind him and deny the fact that Is Jack that Liz wants.
I believe, maybe just maybe, that liz will do something for Jack or vice versa that will make William realize that these to are willing to do anything for eachother and that thier destiny lies with eachother to be together. IMO
Like the plot outline said for AWE: There will be alot of betraying and yada yada yada we already know! lol There was also betrayels in cotbp and dmc-they are pirates hello not monks.
We're certainly gonna face some backstabbers, but its all about being pirates. Will has certainly done it and he will in AWE. I believe IMO that Will will do something very drastic maybe not deadly, hopefully, but something that you kind of wouldnt expect of him. Its al about teh process of changing the characters. Like what happened to Jack, you dont expect him to fall for a girl and sacrifice himself for liz and not for the ship. Thats something that the audience did not expect and i definitley hit the billion mark.