Hes already been here 4 years, of course he'll be gone within the next 18 months - rare for a player to stay that long at a club these days unless it's one of the big clubs.
Transfer window closed. Theres always going to be false rumours. How else would football journalists fill their rags or twatter accounts. Manager visits clubs games. Journo "who are you looking at." Manager "Erm a few I've come to look at" Journo next day. William's a target for said club I would love to know what percentage actually come true. Some guesses will hit the mark.