The game was set two centuries before Ishin, and centred on the famous swordsman Miyamoto Musashi.
In the game, Mushashi looked exactly like present-day Like A Dragon protagonist Kazuma Kiryu, natch.
Everything would have to be improved, and dramatically.

RGG Studio have revamped PS2 and PS3 Like A Dragon, or Yakuza, games before, though.
Maybe well see a Kenzan remake further down the line?
Like A Dragon: Ishin is out onSteamon February 21st, 2023 for 50/$60/60.

Ill let you know if any more rumblings about a Kenzan remake pop up, Majima-style.