As I said before, the title – and especially position – of First Lady has always seemed wrong for the USA. Now, however, would be a poor choice to drop an honary title down to that of a lesser nobility.
Then again, there is that other quaint custom in the U.S. of calling a past President, “President”. So maybe we could see the really confusing position of a President’s husband being referred to as ‘President’. That could be fun to read in the newspapers!