To my understanding, Rathalos both in terms of armor and in terms of the actual monster is the poster child for MH. You see this with the Mii costumes and Hunter's appearance in MvCI. For him to be in this early paints a picture to say that the Mii costume got upgraded into the actual monster. Ther could be more as MH is big in Japan as was a star on the 3DS and is coming to the Switch. However, to me, this seems as though, with that series especially the "main" character is already in Smash, and no one else has as much fanfare as him. Could be wrong but that's what it seems like.
Rathalos is definitely for all intents and purposes the "face" of Monster Hunter, and if you want my honest opinion on this I think Monster Hunter would be served just fine with Rathalos as a boss if it had an actual stage and more music and spirits. It's still kinda confusing to me why they didn't go all the way with that... which is part of why I've been prepared for the addition of more. The Hunter themselves is more of a vessel to experience the game than they are the icon of the series, and I'm not a huge generic avatar in Smash kind of guy. I could do without Monster Hunter as a character.
That being said - I gotta be fair to the series and recognize that this doesn't matter too much. Rathalos is the "Monster"... but there's another half of that title that's equally significant. At the end of the day, it sounds obvious, but the Hunter is just as significant to the overall experience as the Monster. Maybe not the character themselves (they really aren't a character) but the weapons and combat of Monster Hunter are still yet to be properly implemented into Smash. And maybe creating a moveset distinctly around the idea of hunting and making Monster Hunter somewhat of a trap character, that could be cool.
Which brings us to the next thing:
Now this is a "Smash-ism" but I believe that Byleth stole Hunter's thunder. Because from what I know about Monster Hunter, from the one on the WiiU and World. The Hunter's set is nearly 1-and-1 with Byleth. Which IS a shame but it is what it is.
I mean no disrespect to you and I don't want to sound patronizing when I say this, but it's kinda tiring to hear people argue this when Monster Hunter has SO many different weapon combinations and ideas that you can pull from. Byleth is not the only Smash character to use multiple weapons and I'm certain, Hunter or otherwise, they won't be the last. While you could certainly build a MH moveset that looks similar to Byleth, you could also build like ten other ones that are completely unmistakably different. I think the observation that Byleth plays like MH could have is valid... but I think Byleth is simply one of many different directions that a Hunter could be taken.
And again I want to draw a parallel - but before I do I want to say, I hope it doesn't come off like I'm arguing against Chun-Li because if I haven't made it clear already I REALLY want her to make it. But saying Byleth steals Monster Hunter's thunder is not that far off from arguing that Chun-Li's role, being another Chinese martial artist girl with a kick affinity, has already been filled by Min Min. Which I don't think is right, because these are still two totally different characters who offer completely different content at the end of the day. And well, the giant ARMS, but I think you get the idea right? I think it's a little close minded to think this way is all.
Fan rules and Smash fan reception aside. Chun-Li is the most well known Capcom character. I would argue more so than even Ryu or Megaman.
Chun-Li is IMO the most iconic video game character missing from Smash - she is undeniably very very very significant and this continues to be a great point in her favor. I would never argue that a generic Hunter is a more recognizable
character than her - however I would acknowledge Monster Hunter's gigantic influence in Japan and its recent successes making it one of the most glaring
series without a playable character.
Chun-Li represents herself, as an individual character like Sephiroth, while Monster Hunter represents the whole MH series not unlike Steve or Hero - there's precedent for both of these kinds of decisions. At the end of the day IMO it will boil down to whether or not Nintendo wants to pull for the big name in Chun-Li, or the big new franchise in Monster Hunter. I think both would be fully justified, even though personally character and personality mean much more to me. It's a matter of perspective I suppose.
My main point was just that we shouldn't count Monster Hunter out based on these assumptions, and that I think they have a great chance just as well as Chun-Li has a very solid chance. I think when supporting a character like Chun-Li it's important to recognize and respect her steep competition and just hope she can win out against some other really great choices. I'm sure I speak for a lot of people here in saying I'd be happy with most things they could pull from Capcom's extensive catalogue (my most wanted is Morrigan, but she's obviously wayyy down the list of priorities lmao).