The criticisms aren't anything new; they've been going on for a long time, so I'd hesitate to attribute it to some sort of recent change to a "PC" attitude.
In fact, it was on display in the very first book-length study, William Ready's "Understanding
Tolkien", where he described Tolkien's supposed attitude towards black people as (quoting from memory here) ". . .fine fellows, perhaps, but not in England". What his source for this was, I have no idea. Nor, probably, had he.
In a letter, Tolkien described his concept of
orcs, in part, as having Mongolian features "of (to western eyes) the most unpleasant type". This might now be considered rasist, certainly, but it pales in comparison to the description of Huns in Jordanes: ". . .as for the front of their head, which can hardly be called a face. . .". I tend to think Tolkien drew on this, and similar traditions, in constructing his orcs.
LOTR describes them as "sallow-skinned", and arguments have raged for decades about what that means.