I disagree.
I just don't think the market is really clamouring for another fighting game right now tbh. I mean, Pokken came and went last year with very little fanfare, and that had the Pokemon branding behind it. I know the Wii U wasn't a huge success, but plenty of other 1st party games managed to do big numbers regardless, so the low install base isn't really an excuse.
Many people are pointing to Splatoon's success as a new IP as an example of why this will be successful too, and I don't get that at all. I think there was much more to Splatoon being a hit than it just being the latest new franchise from Nintendo. For starters it was a very charming shooter, a genre that Nintendo was sorely lacking. Nintendo already has a beloved fighting game in Smash though, so ARMS will not be filling a gap that fans are hungry for in the same way.
I know this is very subjective - but I just don't think that the style of the game is going to appeal to the masses. It's a little too quirky imo. The character designs are weird and don't have that same cute appeal to them that the Inklings do. I think Splatoon had a very strong identity from the very first time it was shown - the music in particular really stood out. I've watched everything Nintendo has put out about ARMS and I can't recall any of the music at all. None of the fighters really appeal to me from a design perspective so far, either.