This is Soul Calibur V's fault; it lacked content and modes, its story was an incomplete mess and the character customization was underused, showing that most of the development when to the online mode that people stopped playing after two months.
The lack of Arcade Mode endings and the pathetic story mode made the game unappealling to casual fans and its gameplay, while decent, was not as engaging as SC2 or even the slightly unbalanced but still good SC3 for fans of those games.
Unfortunately, Tekken 7 has suffered the same thing with the lack of Arcade endings and content but due to brand recognition has managed to sell well.
With games like Injustice and Mortal Kombat (love'em or hate'em) having a lot of content i.e, full story modes, Arcade endings, a comparable skill gap and now character personalization with Injustice 2. PS/Namco has to step up their game if they want to compete.
The fact that Namco considers the Free-to-Play game part of the franchise says a lot about the state of the series.
As of July 2016, no game has been announced.