True. It's not "was" though, he still isn't.
But being liked by Congress is not exactly a feather in the cap this election cycle. Yes, they will have to work together at some point. Trump can do that. He can also fill a stadium at the drop of a hat, if Trump needs the help to force Congress's hand, he'll get it.
Ironically, McConnell is the most hated Senator of all among the voters.