What did he expect? Does he not know the number 1 focus of Disney's Star Wars
He played one of the least marketable characters in the movies. The focus was given to those who sold the most merchandise in the trilogy, Ray, Kylo and BB8. Ray sold to small girls, feminist, activist, and general SJW/Tumblr type who only cared she was female. Kylo sold to anyone who had the hots for him/characters like him (see Zuko) or people still obsessed with Darth Vader. BB8 is cute robot, 'nuff said.
All the other characters had little to no marketing appeal, regardless of there being plenty of merch for Fin and Poe. Character's like Rose and purple hair lady came off as mean spirited bullies who the audience is being forced to have to like and the rest that aren't from the OG trilogy are just forgettable. Disney doesn't give a fuck about you if you don't make them money, and Fin didn't. How often do you see a toy, shirt or object of Fin compared to the same object of Ray?
Race had little to do with the decision to push an already side character further to the side. This isn't Lucas' Star Wars where it's just a passion project with a giant budget. Disney wanted that merchandising money and while the OG trilogy gets that, the new trilogy got very little in comparison.