You certainly underestimate the power of waifus.
60,000 people spent ~$500 on the Bluray discs for the GBF anime according to Oricon. Keep in mind that's only about 3 hours of video or not much longer than a Hollywood movie's length and they spent $500 on it. It also wasn't very good. So yeah, I easily think Granblue will push PS4s, especially if Cygames includes very desirable codes for the web game.