This isn't some new movement. This is just old mainline liberalism repackaged. Nuechterlein is a minister in the "Evangelical" "Lutheran" "Church" in America. There have been some good Lutheran scholars in the ELCA such as Gerhard Forde but for the most part the ELCA in its liberal leadership looks a lot like the ECUSA. Even the "conservatives" within the ELCA often sound more like Methodists than Lutherans. What is it that makes the ELCA Lutheran? What is it that makes Nuechterlein a Lutheran? Is it because he's German? So is the Pope. He denies justification by faith alone, sola Scriptura and all kinds of other things. The Lutheran confessions teach a satisfaction model of the atonement, so wouldn't "the Best of Lutheran theology" also teach that?
Unlike many confessional Reformed folks, I think confessional Lutherans have been more open to recogize the validity of some of the other atonement models. No single model is sufficient to teach about the atonement. It is a great mystery and can't fit inside of our heads. But you can't be a confessional Lutheran and deny the satisfaction model. You can't confess what Scripture confesses and deny the satisfaction model. What this article shows is that there are many poorly trained pastors out there who went to "lutheran" "seminaries" that didn't think that teaching historic Lutheran theology was important.
The ELCA, UCC, PCUSA, UMC and ECUSA are already in full communion. I can't see why they don't drop the labels and just become a single denomination. They could just become the "Mainline Liberal Church in America" or something. Or maybe they could all become part of the UCC. I'm guessing that they realize they would lose funding from some misguided donors if they did this but I can't think of any theological reasons for them remaining separate in any way.