It sounds like the remake of Yakuza for the PlayStation 4, Yakuza Kiwami, has done well for Sega- well enough, at any rate, that it seems like the company is now open to PS4 remakes of the other games in the crime drama series.
During a livestream earlier this week (via DualShockers), Producer Toshihiro Nagoshi mentioned that Yakuza: Kiwami had done exceedingly well since its release, selling half a million in Japan and Asian countries alone, and that that had prompted Sega to consider remakes of the other Yakuza games for the PS4- these would include Yakuza 2, 3, 4, and 5.
While this does not count as an official announcement, it is clear that Sega is exploring the idea to the extent that they feel comfortable enough floating it in public. Hopefully, remakes for further games in the series are announced soon. Meanwhile, Yakuza fans in the west can either pick up Yakuza 5 for the PS3 (free this month if you are a subscriber of PS+!) or wait for the release of Yakuza 0 on the PS4.