I bet Sony is wiping a whole lot of sweat off their brow that they never followed up Playstation All Stars Battle Royale. We can talk about Smash having to clear a low bar with regards to representation, but that bar was set by their competition, and as long Nintendo doesn't
include a literal Nazi, in the least diverse roster ever, with black characters sealed off by DLC, they get to enjoy the peace of mind of not having the absolute worst representation in fighting game history. (Not many games allow a player to assault minorities as a Nazi. PSABR provides this.)
Smash Bros. is more popular than it's ever been, so boycotts will be ineffective, as will ruminations of how much
more it could sell. Nintendo's probably not going to change, so pleading to them from overseas probably won't amount to anything. However, I see that Sony and to a lesser extent Microsoft are much more local and accessible (at least for Americans) so I think it's likely up to them to change this pattern from their own diverse lineups and compete with Nintendo on that front, and hopefully show them a better way. Nothing breeds adaptation like competition.
Of course that may be a small hope. Microsoft has diverse enough IPs, but they'd rather be in Nintendo's game. So it all falls on Sony, and I think they do a great disservice to their fans that they don't at least try to compete against Nintendo in the crossover platform fighting genre.
Just... Change that roster. One of that Nazi guy's select quotes is "I will slaughter them all." Je-sus.