I am not surprised to see Williams cut... He was mediocre, at best, during the two game he played in. Granted, he played more of a coverage OLB position, but he still wasn't great..
Something to keep in mind. The Patriots did not have to release Williams to sign McKenzie. They had 2 or 3 open roster positions prior to the signing...
As for what happens to McKenzie, only time will tell. In all likelihood, he'll be heading for the IR, but if it wasn't a full tear of his ACL, then there is an outside chance he could return in November..
Anyhow.. Things are starting to pick up,.. And the roster is slowly dwindling..