It is. When I hired last summer the Galvanize full-stack course was all Ruby/Rails. By this winter/spring it had shifted to full MEAN stack. I get the sense that it's an industry shift. (Which I personally find a bit frustrating...)

I think Maker Square does Mongo, not sure. Most I see are still SQL-based as they should be. Mongo isn't used that much... and probably less than a few years ago (seems like it has gotten bad press).