The NBA is already getting the benefits of international popularity. They sell jerseys all over the world, and they pull in talent from all over the world. The NFL is doing OK on the jersey selling, but they’re not pulling the global talent. And given that American Football will never be in the Olympic (which played such a big part in basketball’s growth) or any other international competition if the NFL wants to get audience (and talent) from outside America they need to grow it themselves. That’s really what the American Bowl series (going all the way back to the 80s) has always been about.
I think it will be decades before the NFL ever puts a team in Europe. It isn’t much of an international sport at all. We’ll see NFL teams in Canada and Mexico before we see them over there.