Excuse me if it sounds flippant, but if we really knew the answer to that question, we'd also be able to find the things you speak of.
That said, the game is but a few months old, so consider how much was understood about the other Smash games' mechanics and metas at this point in their respective lifespans...but also consider that we have more precedents than we ever had with previous games...but then again, this game is a new beast...which kind of takes things right back to my initial statement, that is to say, who knows?