Might not be a stage though. Could just be a Story/Adventure stage and not one that you can pick when fighting just smash like.

Here is the thing. If you carefully watch the video again he says comment that "he can show up as a boss". If it were a story mode wouls they make that comment?

As in he can be a boss or an assist trophy. 

I'm not saying it can't be a stage, and I also don't believe that 103 or 100 is the max # of levels we will get.
I'm just saying that as of right now, I'm just going to assume that "stage" is nothing more than a story stage until told otherwise.

The game is large enough with all of its characters and stages that whether or not we get anymore is irrelevant to me. More is always good, but I'm not going to complain if that ends up not being a playable stage.

I believe it will probably be a stage, but in the same sense the biggest argument against it is staring at us in the face. We had a huge clear view of the stage being showcased. The dragon flew around, and fought people on it for quite some time. It wasn't like a quick flash. Yet despite how anyone with half a brain could see that is not a stage we have seen before, he did not include it in his 103 stage count.

Also he didn't say OVER 103 stages, or Over 100 stages. He just said the number. With songs, we got over or roughly. With characters, no amount has been stated. Stages is like the only concrete number we have gotten. Does that mean that it is the final number? Maybe, maybe not. For now, I'm going to assume yes that is final.

Edit: BTW, anyone know how many stages are missing that have been in past games?

Thats true, stage does look like a more level ofnsingle player (completely flat), who knows. Im satisfied with the game now. Even if nothing else was added so i agree

I mean the wording of it "he can" seems like a random thing like how the other stage bosses work. In SSBB, Rayquaza and petey prihana show up as bosses 100%, they wouldn't say "they can show up"

Of course its nitpicking a bit but time will tell. Just strange how he worded it. Stage does look more single player focused so ill go with that for now

Ok nvm now, its shown that only 1 player is on the map when fighting that MH dragon. Boss rush or story mode confirmed

First off, while the text says "he can show up" sakurai (or the translator) says "he appears as a boss".  

More importantly, the word can could be used to express possibility, but also capability.  Like, if I said "I can speak English or Spanish" I am not talking about probability, I'm just listing two things I can do.  

Also, I think it's interesting that they alluded to the hidden mode right after showing Rathalos, and that they seem to have a mini cutscene for him.  All signs seem to point to him being a boss in a subspaceish mode.

Just wanted to give my opinion on the Rathalos thing, is that the footage we see him in is most likely from a Boss Rush mode, like Brawl had, because if you look at the Dracula footage there is only 1 time that he see more than 1 character fighting him(unless I'm competently misremembering but at the very least in the Simon trailer, Simon is the only character on stage before Dracula shows up) , the cutscene could literally be just for the Direct,like the zoom in on Dracula while he was siting,and to where you fight him in that a location from MH4(or so I was told), so that is also most likely a stage in the game, yes Sakurai did say that Ultimate had 103 stages, but at the bottom of the stage selector there is room for at least 6 more, now I normally don't like this type of speculation, but in a game like this it feels weird that they would go that far and leave it like that, plus while they were specific in saying 103 but they weren't when talking about that nº including FD and Battle Field form just saying 300+ instead of 309.

And finally assuming that Rathalos is part of a story mode, my question is why would there be a boss plus location from MH in the story without a MH character, and if a MH character is in why wouldn't they get a stage?

No one else noticed that the is a custom balance option then?

https://www.youtube.com/watch?v=v4xZ8MIKXAU

I am hoping for a story mode. The prospect of a Castlevania segment... 34 songs, Dracula and Death as bosses, makes me REALLY want this game.