First, we are talking about plans for a single workplace holiday party in Boston. It's unclear why you are bringing in your shallow interpretations of data on violence.
In any case, your statement is of course true -- in segregated areas of the US, which describes most of the country. Rates of violence are, obviously, higher in impoverished areas (which, due to systemic racism, are for the most part majority PoC). Your statement is like saying that people living in California are a higher risk of violence from Californians than New Yorkers, as if that proves something about Californian tendency toward violence.
Interestingly, and unsurprisingly, this "fact" simply isn't the case in integrated areas. Which is exactly the point. Risk of violence is driven by poverty, not blackness. Ask Appalachia what race is perpetrating the most violent crime.
Personally, in all of the (thankfully few) times I have been physically attacked by strangers, including shoves on the street or food thrown at me in a park, it was by white people shouting racial epithets.