I don't believe it. If true, that would be revolutionary information. Millions of people have been taught that lager yeast is a different species from ale yeast. Related, but different species.
Hardly revolutionary in biology to reclassify organisms - either deciding that two species are the same or splitting strains into distinct species. It happens all the time. Just look at dogs if you want to see the diversity that can come from a single species. Or humans - some can't digest certain things (like lactose) and some can.
So lactose-intolerant folks are the ale yeast of humans?