I'm with you on this one. I sort-of get how this could trigger some
people's radar, because there is a not-very-proud tradition of white
people dressing up as black, but this is pretty far from that. As you
say, it's not blackface, nor is it a case of someone dressing up as
Generic Black Guy because he thinks it's OMGsofunny! It's an
imitation of a specific celebrity, and it isn't done in a way that
exaggerates or mocks racial features.
Anyway, I doubt this is a story with any kind of legs. Right now it's
just at the "some people on the internet objected" stage, and I expect
that's where it will stay. I doubt you'll see a league investigation
or disciplinary action or even an apology (except maybe of the "I'm
sorry some people were offended" notpology type). Maybe there will be
some discussion of league social media policies, since this all got
going from Bissonette posting pictures from a team party, but that's
about it.
Jim