Klentak didn't choose Williams. And I don't think if the current group was doing that trade that they would have accepted Williams and Alfaro, two prospects with poor plate discipline. Plus Williams didn't come with a great work ethic. So I don't think they have any real attachment to him, but they might want to wait a year before moving him (Haseley and Moniak are both LH OFs, as are Pullin and Cozens).
Williams has to learn to think, he's behind Hoskins, Herrera and Altherr, Kingery is probably more talented (and with a little experience, will probably be a better fielding OF, he was an OF in college), and Santana isn't going anywhere. And two LH high 1st rd picks are only a couple years away. So it would behoove him to work hard, impress people with his attitude, and take advantage of his opportunities - because he's basically showcasing himself for a trade.