A little bit of a heated subject, but Nintendo is REALLY pushing Fire Emblem as a phoenix of a series ever since Awakening.
That said, I expect to see Fire Emblems 15 and 16 to come before Smash 5. For the scope of the series... I honestly believe we'll see
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cut and have one more newcomer by nature of the growing series in both roster and popularity. And there are 3 paths to truly take.
Fire Emblem 15/16 Protagonist - Not.. much more to say. The "Flavor of the Month" kind of mentality of things; especially if they have something unique to offer like the Magiknight approach of
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and dracomorphing of
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. Besides this... there are two characters with any level of reocurrance, popularity, and importance to note. And here's a hint... the 25th anniversary artwork.
Anna - The "second mascot" for the series. Single most reoccuring character. One that Intelligence Systems loves using (based on how much Annas showed up throughout Awakening's DLC, MAKING HER THE HARDEST BOSS OF THE SERIES, and other things...). With an in-universe excuse to effectively use anything besides transformations in her arenal but most predominantly bows, lances, staves, swords, and hidden weapons. The more that she gets used as a token secret character and used at the forefront for the promotional material of the series the more likely she becomes.
Tiki - With Corrin... her chances legitimately decreased by a significant amount. But this fan-favorite manakete is still one of the biggest names for Fire Emblem... even being put as the main face for the Fire Emblem cast in the most recent spinoff.
I'd honestly expect either Anna or a "new protag" make the jump for the next roster, to be brief.