Whitmer obviously won't take this race for granted, but all of the polls we've seen over the last year have had her favorability/approval pretty good, even despite Republicans hating her. But given that restrictions are receding, I don't see why that would even be a real issue for her in 2022.
Even with COVID, Democrats improved in Michigan. There might be parts of the country that will be unnaturally conservative the same way some were unnaturally liberal after the farm crisis but it’s not going to be Michigan.