Even if they do succeed in that goal, I'm not sure the result of more researchers follows. Most of what they're targeting is replacing bachelor-level education, for one thing, not PhD-level. But more importantly, research is currently more constrained by funding and positions than availability of researchers. When either a university or Microsoft Research opens a position, they get hundreds of applicants. Even for postdoc jobs there are many more researchers than jobs. If several physics departments have to close, thousands of new students who've successfully taken physics MOOCs isn't going to make up for the closure of those research labs, from the perspective of progress in physics.

It's possible something else could replace those physics labs. Maybe Microsoft Research and similar non-academic labs will get larger, and expand out of computer science, more like the old Bell Labs? The U.S. could decide, alternately, that funding research is a priority, but doing it via hybrid educational/research institutions (the classic "research university") isn't going to work anymore, and choose to fund research-only institutions, e.g. bring the national labs back to the forefront. That's plausible, but I'm not sure there's political support for it.