We shouldn’t be looking for “only characters who will happen”, since history has shown that whenever the Smash fandom takes that mentallity it backfires at big scales.
Rather than that, we should take an open mind approach. Consider many kinds of picks in general, do researches on certain characters or companies and what have they experienced with Nintendo in general, take into account how received a character tends to be received around the world overall, check recent partnerships Nintendo has done.... all also while preparing ourselves potentially for the unexpected.
It’s more about taking in mind many scenarios while always considering that even stuff outside of them could happen.