I think FE Warriors will probably get amiibo. Maybe not for every character, but for major characters like Chrom who have yet to get one, and then characters like Marth will receive a new one (you can't have an FE amiibo line without Marth after all).
Hyrule Warriors didn't have amiibo because the original game wasn't built with amiibo in mind to begin with, and that still held true for the 3DS port because it's not like they could add much in the way of unique amiibo support using the existing set-up for the game (plus they had bigger development priorities, Hyrule Warriors had some notable blemishes that they improved on in the 3DS verison).
Also while I don't say this to put down Chrom fans or anything or make his inclusion seem lesser, I don't think Chrom will be the "main character" of Fire Emblem Warriors, and I hope he isn't (don't type an angry reply just yet, it's less negative than it sounds
). I can understand why people think that, as most Nintendo fans' experience with a Warriors game extends no further than Hyrule Warriors, but Warriors games (even the ones based on licensed properties) normally don't have a single main character. Hyrule Warriors only did this because Zelda games aren't normally these complex stories with morally grey characters - Link is the hero, Zelda is the wise princess whom he must assist, and Ganondorf is the dark power threatening to take over, and that's the end of it. Everyone else is there for fun and world building.
I think the best point of comparison for FE Warriors is the Dynasty Warriors Gundam games. While Gundam may be an anime franchise in a sci-fi setting, it's still very similar to Fire Emblem in that it's all about warring nations and young prodigies become pivotal players in war. And it has three Dynasty Warriors crossover games, using characters from all across the main Gundam timeline, and the side franchises.
I played a lot of Dynasty Warriors Gundam 3 a good few years back, and personally, there's a lot of elements from that game that I think would lend themselves perfectly to Fire Emblem Warriors. The main thing I loved, was how the story was handled - instead of simply choosing one main character from the entirety of the Gundam storylines (each Gundam series generally has a new protagonist each time, even if old characters return), they instead made an original story that focused on characters from across the Gundam franchise being dragged into a strange new world, and finding themselves allied with characters from other Gundam franchises. This meant, for example, that heroes from one series could be allied with characters who were portrayed as another series' main antagonist. The allegiances formed were somewhat based around what kind of ideals the different characters had regarding war. The story was split into four parallel arcs with their own title:
-Those Who Understand
-Those Who Doubt
-Those Who Pass By
-Those Who Fight
However, upon completion of these four arcs, the tides of the war would change, and characters would shift their allegiances around in accordance with this. Two new branches would then open up - "For Peace", and "For Victory". With most of the good guys from the shows now being together on For Peace, while most of the antagonists were now together on For Victory.
HOWEVER, after those two arcs, a new threat emerges, one that requires the military might of both sides. So every character now joins together to form one massive army, and a new, final arc opens up, called "For Reform".
In addition, they also had "History Missions", which were missions set aside from the main story where you could relieve iconic battles from the Gundam shows as playable missions.
Personally, I think Fire Emblem Warriors should handle it's story in a very similar fashion. With so many characters with so many ideals regarding war, it only makes sense, and IMO it would be way more interesting than just picking Chrom or anyone else as the sole protagonist (not to say Chrom couldn't carry a game on his own, I just think it'd be wasted potential to have a sole main character here). Even using the story arc titles from Dynasty Warriors 3 as a reference, I can easily see how some characters would be aligned. For example, characters like Marth, Chrom, Elise, and Eliwood would fit perfectly into Those Who Understand, since they're all about helping people and fighting for peace. Corrin would fit into Those Who Doubt, as he/she has great inner power and has had to make some rather difficult decisions with big consequences, causing some doubts in his/her mind about whether or not their path is right. Someone like Gaius or Azura would probably be recruited in the Those Who Pass By path, as they are pretty neutral (I define Azura as a True Neutral character because while she does want peace, she still will take whatever path Corrin chooses to achieve that, regardless of the morality of it). And of course, villains like King Garon would fit just fine in the Those Who Fight path.
And of course, you could easily make an equivalent to History Missions with Fire Emblem.
TL;DR - I think FE Warriors would be better with different story arcs featuring different crossovers of characters based on their ideals regarding war, rather than making a generic Light VS Dark story featuring Chrom or anyone else as the main character. Dynasty Warriors normally does this kind of thing and it's perfect for Fire Emblem. Hyrule Warriors only kept it a simple Light VS Dark story since that's what Zelda games normally are.
