history.berkeley.edu
The immediate problem I see with that letter, if there is one, is that there only appear to be 2, maybe 3, male POCs listed among the UC Berkeley history department staff (though an additional 2 also do not have headshots). Supposing the letter could be written by a woman (it's tenor feels like not, but perhaps), there could be another 4-5 women on the staff that seem to count as POCs.
Gonna be pretty easy to narrow down who wrote it, or conversely, to ascertain if it actually wasn't written by a UC Berkeley Dept of History Professor.