Don't think so . . .
I just can't see it. Combining various races with various classes has become a major aspect of the game - seeing just how this combination works compared to that combination.
Thematically, the world is supposed to have many races - to the point that major cities are often portrayed as an almost even mix of all the major races in the area (which can number 4 or 5 races, easily). Personally, I see that as odd, but having a fantasy world with multiple races is a sacred cow I doubt they will ever even consider killing - or even tipping. Actually, I can see them milking it, adding quite a few more into the mix every year.
Now, what I worry about is not having only humans, but having non-major races in the PHB. I can see humans, elves, dwarves, (half) orcs, and halflings, but . . . tieflings ?! warforged ?! changlings ?! shifters ?! and so forth are just . . . odd. They do not have entire regions and countries composed of only these races. They are fringe races. They should be offered as races in PHB2, PHB3, etc. Major races alone should be in the first PHB.
An elf walks through a major city - even in a human dominant area - in a typical world in D&D, and a few eye brows are raised. A warforged or tiefling walks through the same city, however, and it should cause quite a start. Some would not even know whether to treat the warforged as an individual with self will or an automaton / golem servant of a powerful wizard, sent to buy supplies or fulfill a task. A tiefling - a being whose physical form shows their insidious, fiendish ancestory - I can see such being refused service at most shops, inns, etc - just out of worry that word might get around that they would serve such as that in their shops, etc - and thus drive away the (far more numerous) more normal customers (which, oddly enough, includes dwarves and elves and halflings, usually).
At least, this is how it seems to me.