Don't you think it's strange that most of these characters that have been claimed to be in, or DLC, all have trophies?
Not really. Lots of characters are going to have trophies.
Dixie Kong, K.Rool, Mewtwo & Wolf are all important characters in their respective series. They were going to have trophies regardless.
Ice Climbers not having a trophy would also be really weird to me.
The only one you could consider weird is Chorus Kids/Choir, but even then, they are one of the most notable minigames across the series and were literally the only thing on the NA box art for the DS game.
There's almost 700 trophies. Probably everyone anyone wanted has a trophy, so it doesn't really mean a whole lot.
What DOES mean something is characters with brand new models, or if they are clumped in a certain way (for example, all the Pokemon that were cut or intended to be in Brawl were next to each other in their own group).
Mewtwo's model isn't as big of a red flag though. Like Brawl's, the model doesn't really match the style of the fighters, so that model is likely not what would have been intended if he was going to be in.