In a perfect world, the impact of religious doctrine would be limited to its followers. However, in our current world, religious doctrine seems inextricably intertwined with politics. So, I think and acceptance by the leader of the Catholic Church would have an impact well beyond practicing Catholics. Keep in mind that six justices of the SCOTUS are Catholic.
And yes, directives will have impact far beyond responses in a press conference, but the latter may lead to the former. At the very least, these are positive words that directly contradict those of his predecessor.
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson