>>7126589941. Marie Rose and Honoka were just the flavors of the month. Newly introduced, so of course they're going to trend high during their debut and throughout their "honeymoon period" so to speak.
2. Japanese consumers have notoriously low taste. They consume gatchas on the regular, and don't really care about character development, as long as the girls are cute.
3. There's a right way and a wrong way to do things. Just because Japanese audiences enjoy cuter characters, that doesn't mean you go for the most basic, unfitting character. You can marry the ideas of cute with the overall style and energy that Itagaki was known for. Hell, he's done it himself. Half of his girls are various kinds of cute and demure. He just did it in a better way.
4. You never really justified that concept that the inclusion of Marire Rose and Honoka are actually necessary for capturing the Japanese audience. Being exclusive to Xbox was in of itself the main issue, since Japanese players didn't adopt the Xbox brand. So merely by going to Playstation, they would experience an uptick in sales. You give that credit to Marie Rose and Honoka, with no real justification.
Any fighting game franchise has to introduce new characters in order to remain fresh long term. So new characters were coming regardless. They could have been better characters than what we got, and the series would still have seen an uptick. Perhaps even a larger one.