Per zagsblog.net, Donald Williams no longer has any interest in Marquette (and vice versa) or St. Johns - apparently (and following commitment from Buycks) MU never followed through on setting up visit for Williams to Marquette campus. University of Houston and Marshall are only two schools currently interested in Williams.
I think Williams fell out because of McMorrow, not because of Buycks. Buzz was looking to use the scholarship this year and chose McMorrow over Williams.