Man, how in the world are they going to differentiate sword users? I't's not like they have two characters that literally share the same name and use the same sword n shield setup or anything...
Moveset isn't really an excuse to exclude a character, Sakurai has proven to be creative enough to pull stuff out of nowhere.
Yeah but Link is much more than -just- a Swordsman. He uses a variety of tools and items which further round out his moveset. You can't say the same for Fire Emblem lords, who have a much more limited pool of unique options to draw from by design.
Chrom is no doubt going to have a unique moveset, but what is going to be his IDENTITY? Fast swordsman? Medium speed trickster? Heavy hitter? Duellist? As a character, he has no inherent niche he fills, unlike Link, who can be summarised as "Sword and Shield user who also uses a variety of weapons and items"
Marth is "A quick, skilled swordsman who wields a thin blade with one hand." Ike is "A rough but powerful swordsman who uses a great sword and carries the power of Aether"
Chrom is "An agile swordsman who wields a sword in one hand." he has no real 'catch' to his design. He doesn't have aether, he's just another quick, well-rounded FE lord with a one-handed sword. He's been shown doing acrobatic moves in FE:A trailers but that's it. Aside from the rather obvious buzz-saw attack he does when fighting Luciana and the issen-like cut-through he performs, he doesn't have much to draw from that really defines who he is.