He was not demoted as you say, it is customary for those raised to the bishopric to be 'Bishop of Someplace'. It is normal for those who work in the Vatican government to be titular bishop of an ancient, now defunct See, sometimes one in Moslem occupied lands.
Francis removed him as Papal Nuncio to the US at age 75, he might have stayed until 80, but he offended Francis over the Kim Davis meeting and so was replaced at the normal age.
He is one of the bravest Knights in all of Christendom.
I stand corrected. Not an expert on Catholic matters.