I mean... Most of those points seem kinda flimsy IMO, no offense.
- "Kazuya has combos" Terry also had combos and Kazuya still made it in.
- "Sephiroth overlaps with his visual design"... Not really? Maybe it's just me but they do not look similar at all. The only thing they share is the white hair.
- "Both Min Min and Byleth switch weapons" Min Min still got in despite Byleth having different weapons. In any case, Byleth doesn't really switch weapons in a literal sense. He/she uses a different one depending on the direction of tour attack. Min Min is the one that actually can switch weapons.
- "Joker has guns" Yeah, but if that is a point against Dante then that should be a death sentence for the likes of Doomguy, Master Chief or a Resident Evil rep, and all of those would use guns in their moveset a lot more than Dante.
As for DMC not being as huge as RE or MH, that's true. But at the same time that point can be applied the other way around. Both Mega Man and Street Fighter got in before Resident Evil, despite being smaller series in terms of sales and popularity worldwide.
That happened twice with Capcom so I don't think it's that far fetched to imagine a third time.
I get your reasoning but my problem is that most of these points seem weak to me, and in any case, not exclusive to Dante at all. If anything I think he is in a better spot than some other characters even if what you said is true, because Dante's arsenal and abilities is almost endless and it would be hard to tell how they would approach him. They could go full with his style switching, or maybe focus on him having ton of weapons. He has Devil Trigger which could be added as a meter, or if Sakurai feels creative he could even implement a Style meter that goes up according if Dante does different combos or doesn't get hurt for a while, like in his games.
They are not really comparable
Mega Man and Ryu are some of the biggest gaming icons and there's no question to that, meanwhile Dante is unfortunately nowhere close. Same reason PAC-MAN got in.
Kazuya is way more combo heavy than Terry, bad comparison. One of his attacks is literally a 10 hit string. Dante would also have a demon transformation (DT) which would heavily overlap with Kazuya's, ''weak points'' lol.
Min Min and Byleth aren't in the same pass but ok.
Seph and Dante have way more in common than you think, big swords, coats, they're tall,, and have white hair as you said. If they gave Dante a shirtless alt he would look nearly the same as Seph too. Forgot to mention the fact but didn't Isaac fans stop talking about him once Cloud got announced? I don't see why the same wouldn't apply here.
Sure, Dante's moveset potential is insane, but in the end it would just make him harder to implement, not to mention it would be a balancing nightmare.
Thing is most of the stuff that would make Dante unique has already been taken by another character, and most of them are in FP2. He also has heavy competence with other Capcom reps which is a fact we shouldn't ignore. As I said earlier, even if I want him in doesn't mean I can't see why he isn't as likely as I'd want him to be. I really don't get why you felt the need to make such a huge post just to prove I'm wrong.