I'm an optimistic person, but I think that the whole model railroad hobby will continue to contract. I'm 45 and I have a 12yr. old son. He loved trains as a young kid, but now video games are his hobby of choice. I see the same thing with all of his friends. It's not that he doesn't enjoy a train now and then, but given the choice he will always choose a game. His generation does not play with toys the way previous generations did. The entire toy industry is feeling this shift.
It isn't good or bad, it just is what it is. We are passed peak model railroading. Does that mean it goes away? No. Does it contract? Sure. Will technology continue to improve and offer people access to products, services, and communications re: model railroading that haven't even been thought of yet? Absolutely.