Two people just posted their FP2 predictions so I guess I’m doing mine
CP6: Ribbon Girl. She’s practically the most important ARMS character besides Spring Man who could still get in despite him being an assist trophy, but Ribbon Girl just seems a bit more new and fresh since he’s already in the game
CP7: Tracer. A bit of a weird pick, but Tracer is from a super popular game from a genre not that represented in Smash, and she has a very unique iconic moveset potential
CP8: Steve. Minecraft is literally one of the best selling games to date surpassing even old classics. Minecraft has had a huge impact on modern gaming and it would make perfect sense from a marketing standpoint for a number of different reasons, and this reveal would be a huge shock to all of us for the better
CP9: Corviknight. Nintendo clearly wants to represent their newest games, as seen with Byleth being in the game and Corviknight would represent Sword and Shield nicely while also adding a Pokémon that’s not just the usual “furry,” for lack of a better term, we’ve gotten as Pokémon characters. Corviknight is fairly popular, but isn’t the most requested Sword and Shield rep, although in my opinion he is one of the most memorable Pokémon from Sword and Shield. Although already being a spirit would be a hurdle, but not necessarily a deconfirmation
CP 10: Arle. Smash desperately needs another puzzle game rep. And one who actually has a unique moveset based around puzzle games. I can’t imagine her moveset being anything but iconic and unique and it’s nice to get another female character.
CP11: Crash Bandicoot. Nuff said
Without going into details, this impression ended up being wrong. How much of the events of XBC1 are spoiled by XBC2? Honestly for each individual person it's dependent on how they react to it.
If you just go by what's in the game itself of Xenoblade 2 you'll mostly be ok. At worst you'd just be curious about how some of the connections work. If you try to look up a few more details on like a wiki or something, you may be spoiled about things involving Xenoblade 1 that you didn't intend to find out before playing. I would know, that happened to me -_-
Long story short there's not really much issue with starting with 2 instead of 1. But starting with 1 is TECHNICALLY the safer route in terms of spoilers.