On a serious note regarding the fighters pass predictions, I think we're all severely underestimating the first-party characters.
On a very basic level, creating and selling something based on an IP you own is much less of a headache both in the near and long term. But even past that, Smash will likely outsell any other individual game on the Switch, meaning that Nintendo's other releases have a lot to gain from the exposure of being included in Smash. They don't need to pick a character to convince you to purchase the DLC so much as they need to benefit from Smash-centered social media and tournaments acting as free advertisement for their other IP.
I think they started off with Joker to start with a bang and keep as many people intrigued by what the pass will hold as possible. I don't think we'll have many other surprises as wowing as that one was. And I think that at least one of the characters in the pass is one we couldn't even guess because we don't know it exists yet. We still have a whole E3 and Christmas season to get through before the Fighters Pass is complete, and yet we're making our bets based on current information. Think of it this way: at this time last year, none of us even knew Smash Ultimate was a thing, let alone who'd be in it. What will Nintendo announce in the next 4-5 months that we don't currently know about?