I'd highly doubt it. This Smash has the most merchandising of any Smash in the series before-hell, arguably more than most Nintendo games in general. We've got two versions, limited edition systems, a soundtrack, first party controllers, third party controllers, strategy guides, and, of course, Amiibos. So I feel like it's pretty damn likely they'll take that a step further with DLC.
I'm guessing for Amiibos, we'll see five batches:
Batch 1: Release (12)
Batch 2: February/March: 12 more fighters
Batch 3: May/June: 12 more fighters
Batch 4: August/September: 12 more fighters, most of which are secret characters
Batch 5: November/December 2015: The DLC fighters.
I'd also guess we'll see limited edition ones in between, specifically popular alt costumes (Hoodie Mac, Fire Mario) and Miis (like maybe a Reggie Mii or something-you know, something fans would want, but that kids wouldn't go out and buy).