From the standpoint of someone who was a part of Sm4sh speculation, it's scary to see people get their hopes up like this. People vehemently denying Box Theory or discrediting Vergeben solely because they want more, or they want something different. I experienced similar things occur during Sm4sh speculation. When Gematsu became big people doubted it because it didn't have Ridley or K. Rool or Dixie. Fake leaks like Tower of Smash got attention solely because they contained popular characters and entertained the idea of characters being unlocked if you communicated between the two versions, which allowed fans to continue "speculation" (or keep their hopes alive instead of accepting reality). I also refuse to let people forget that the fanbase took "RIDLEY IS IN THE CLOUDS" seriously, because that's absolutely ridiculous.
Guess what happened when the ESRB leak came out and the Shulk trailer confirmed it a week after?
Chaos. I often go to the example of a user cursing out the entire leaks group, and most of us remember how hated Dark Pit was at the time, as many saw him stealing a roster spot from their character (if there's one thing to be happy about, it's that this argument is all but dead this speculation cycle). Fans of the Duck Hunt Dog remember the ire drawn towards their character because he was the last to be officially revealed, and he wasn't a popular character. Now that we have hindsight, we can realize that Dark Pit was an easy clone to make, and that the Duck Hunt Dog is an iconic Nintendo character, but at the time all that some fans could see is red, and those fans were very loud and caused a lot of chaos in the community.
Expectations are a very dangerous thing. It's why I've made an active effort to address people whenever they say "I expect x" or "y is a shoe-in," because no character is a lock for this game until they are confirmed. Its the same with any theory or leak. The only reason I back box theory is due to the evidence provided, and the fact that any argument against it is as flimsy as cardboard. Of course, box theory itself is based on hypotheticals, but the way that they all come together perfectly makes me inclined to not call it coincidence. When I see people try to dispute it with "Incineroar and Ken can't be our next reveal" or "Sakurai always trolls his fans, there's sure to be more" or making other straw grasps to disprove it I see this speculation scene going down that same route that Sm4sh speculation did, and I don't want that. Especially because this speculation cycle has gotten a lot of people's hopes up for their favorite character, and I can all-too-clearly see those hopes crashing down when the full roster leaks, leading to something worse than the post-ESRB fallout for Sm4sh.
Mind you, it's okay if you don't want to believe box theory. If you want more characters, power to you. I also agree that those who are trying to temper expectations for the sake of the fandom shouldn't be so quick to jump at others. However, if you're going to try to disprove box theory, or argue that we're going to get more characters, you should have an actual argument. I mean examples, excerpts from Sakurai's interviews, parallels with previous speculation cycles (which shouldn't be used as concrete proof like they have been because this is a different speculation cycle, it's a precedent, and doesn't mean much), references to previous game's files, Nintendo's inner workings or current direction, etc. Not just "Sakurai always does this" or "x character isn't in this so I'm not going to believe it." Those are opinions. Not arguments. There's a difference.
Also, if you're going to swing at box theory, I expect an argument comparable to the one laid out for it, which I still have yet to see. All I've seen so far is a disconnected set of hypotheticals varying in quality, none of which compare to the connected evidence for box theory. I also dislike the vindictiveness of those who oppose box theory. I've seen people here, on this website, get hate thrown at them solely for playing Devil's Advocate. Not even supporting box theory, but just saying why it may be true, and getting hate and incredulity thrown at them because of that. This is speculation for a video game on the internet, not a violent political argument or epic battle for truth where one side needs to obliterate the other.
Like, can we just agree to disagree and drop the topic? If you don't believe box theory, fine, but just don't get your hopes up for 5-7 more characters. If you believe box theory, great, I say always plan for the worst and hope for the best, so whatever happens'll just happen.