I'll have to do a bit of a deeper dive into the numbers, but I doubt Grichuk has ever had a BB/K ratio or O-Swing% like this over a 17 game stretch before. Even during the best of his times, he usually posted sub .300 OBP's with high SLG%. Take last September as an example.
His O-Swing% is substantially lower, his BB% is higher, his K% is lower, and there's clearly a very tangible approach change that we all see in his AB's with the eye test. I think it's safe to assume there has been some approach change. Obviously, the 179 wRC+ is likely not sustainable, but if this approach change can leads to a .250/.330/.500 slashline over the course of a full season, combined with his defense, that contract would be a relative steal. Let's hope it sticks, because it's always been mental with him.