Nope. Sakurai said (and people have quoted numerous times) that Lucina was originally going to be an alt for Marth, but they changed her to a bonus character mid-development because they apparently wanted to change her properties. Chrom was never replaced by Lucina, he was replaced by Robin.
Konknitive Dissonance
Oh, okay.
edited 23rd Jul '14 7:34:08 PM by Konkfan7
The Fool
Chrom was apparently considered very, very early on but was dropped in favor of Robin and their Magic Knight -ness.
I sure said that!
Konknitive Dissonance
That's what I'm thinking.
Right. Chrom never made it past the concept stage of development.
That's probably why he's in Robin's Final Smash though. They had the model so they repurposed it for that.
Think we'll get an Assist Trophy from Awakening?
You cannot firmly grasp the true form of Squidward's technique!
KING OF EXPLODO KILLS
Yes. Tin Pot.
nyo ho ho
The Fool
Sumia, Cordelia or Tharja or maybe Gaius seem likely.
edited 23rd Jul '14 8:51:54 PM by Pulse
I sure said that!
Inheritor of the Wing
But wouldn't that assist trophy involve people taking damage for no reason?
KING OF EXPLODO KILLS
![[up]](https://static.tvtropes.org/pmwiki/pub/smiles/arrow_up.png "[up]"){kind=icon}
Someone would what? You just wrote "Or" and then "Someone would eventually". They would what?
Court Dragon
Fun fact: with everyone jumping around the cover art of Fire Emblem Awakening, there's only one character whose face is obscured.
I have a message from another time...
White Hindu
I was gonna say "Triangle Attack", but then I realized that Awakening didn't have one.
"What's out there? What's waiting for me?"
The Fool
Still, I mean, c'mon. Caeda, Elincia and Sumia doing a Triangle Attack would be a neat way to feature all three FE settings represented in one assist.
I sure said that!
White Hindu
Well, except Jugdral, Elibe, and ...whatever world The Sacred Stones took place on. But yeah.
"What's out there? What's waiting for me?"
Either Taguel would make me happy.
Deer
Who was Nes Classic talking about? I've never heard of that character.
You cannot firmly grasp the true form of Squidward's technique!
The Fool
And Sacred Stones took place on Magvel
Darling.
Gamer-turning-maker
Oh shit, Tomodachi Life stage.
Long live Cinematech. FC:0259-0435-4987
Apparently, your own mii's will appear in the Tomodachi Life stage. Essentially, your own islanders are watching a bunch of other Nintendo characters smash up their apartments. 
Gamer-turning-maker
ALL HAIL THE MASTER HAND
Long live Cinematech. FC:0259-0435-4987
... I personally still consider it as Chrom being in smash. A lot can change during development. Maybe last second they swapped Chrom and Lucina?