Cuomo isn't expendable, he's a threat.
And why go after Kavanaugh like that? C'mon... it earned her major points with the feminist crowd by chanting "believe all women." Plus, as a Trump appointee, he wasn't going to get a fair shake regardless.
You're forgetting the most important point though. It's not a secret Biden's on a serious decline. Republicans know it. Democrats know it (knew it before he was elected and pushed forward anyway). The rush to curry favor with the new queen is already underway and will get worse as Biden keeps going downhill.
This is my conspiracy side kicking up and you can take it with a grain of salt. But I just have this feeling the things happening with Cuomo are coming to light because someone wants it to come to light. Hell, the flat ignored one of their Governors in black face and a Klan costume as well as Cuomo ordering thousands to their death. You think this couldn't have been handled much quieter if they wanted?