His forthcoming book is “White Too Long”
https://www.simonandschuster.com/books/White-Too-Long/Robert-P-Jones/9781982122867
“As the nation grapples with demographic changes and the legacy of racism in America, Christianity’s role as a cornerstone of white supremacy has been largely overlooked.”
“White Too Long demonstrates how deeply racist attitudes have become embedded in the DNA of white Christian identity over time...”
“Jones challenges white Christians to acknowledge that public apologies are not enough—accepting responsibility for the past requires work toward repair in the present.”
“More broadly, it is no exaggeration to say that not just the future of white Christianity but the outcome of the American experiment is at stake.”
I guess we all hear things in our own way. Far from cheering the changes it sounds to me like he's lamenting them and offering his prescription, however misguided, to reverse the slide of Christianity.
His diagnosis of the problem may be wrong but he doesn't sound happy to me.