You're not the only who hates leaks.
I find it hard to believe that Fire Emblem is going to get another blue-haired sword-wielding rep. Beyond that overused reason...what we have is a heavy sword user and a lighter sword user, both being blue-haired lords in their respective games. Sure, Chrom could definitely be a playable character, there's zero doubt about that. But what is going to differentiate him from them? Chrom uses Aether too, that fact alone does wonders in further pushing his potential near-synonymy with Ike/Marth. Will he just be a moderately powerful blue-haired Fire Emblem lord? Sure, that could work, but that's a waste of a character slot in my mind. If not, how is he going to be different from them? The only thing that comes to my mind that can separate him from the rest is his Shield of Seals (i.e. the Fire Emblem). Even with that, I could only see it being implemented in the way that Link/Toon Link's shields are used, i.e. protecting from some projectiles from the front while in idle position. Or, it could be used like Pit's Mirror Shield, and with it being the Fire Emblem, it probably could merit acting exactly the same as that.
But with all this, I just feel as if putting in Chrom would seriously be a waste of character. They're not limited to sword-wielding Lords and they don't have to be. They could put in Anna and have her use the Levin Sword, which is a sword with ranged lightning magic. She has appeared in all but one Fire Emblem title, not to mention she is playable in Awakening. Plus her identical sisters (all named Anna) pop up all over the place - in merchant shops, in levels, in the Outrealm, in DLC chapters - so they're very recognizable to at least those who have played Awakening. They could put in Robin, who uses both swords and magic and obviously plays a very prominent role in the story. Not to mention his/her connection with you-know-who. So...sure, Chrom is from the best-selling game in the series. The best-selling game that also saved the series from its demise. I get that. But barring that, what else does Chrom have to offer that Marth and Ike haven't. Essentially, nothing.
Overall, a third Fire Emblem rep is likely. I'll retract me saying Robin is unlikely. But Chrom especially, is unlikely from the way I see it. I think that a Fire Emblem rep who is soley a basic sword user won't make it in.