Identity politics by definition assume conflict among races and identify allies and enemies. It is the starting point for war -
"we chat at such events about being racialized columnists among the Great Whites."
Really? Have you actually looked at the racial makeup of the Globe and Mail staff? Or do you write all your columns from home, in your own echo chamber? My children grew up in multiracial schools and easily chose partners from a different culture. My grandchildren, bless them, are identifiably multiracial. 
How does one manage to get fired from the Walrus, or from the Toronto Star, two of the most socially-progressive  media outlets on the planet? Simple. Kay challenged the dogma of the <alt>L and was bullied into resignation (Yes he was - read his interviews and the tweets).  Cole chose  dogma and lost the support of a newspaper that is already far left of the average Canadian. 
Your enemies are not the "Great Whites". They are the far left. Cross them and your career is done.