Hmm, idk about this, it's possible Davy Jones never even properly ruled as king.
We know he had an entire career of piracy (Something even Xebec says), which meant that he came after Joyboy to some degree, since Soyboy is explicitly stated to be the first pirate and the first man to take to the seas. If Davy actually ruled as a previous king that forced the world to go up against him, wouldn't this mean:
1. He gave up or abandoned his throne to go pirating.
2. Or he lost his throne early on and had to follow Joyboy's example of being a pirate (he did this long enough to establish a career as a legendary pirate), and never got it back from Imu or another king of the AK.
We also know from the vegapunk broadcast, that despite whatever happened before, the void century war ultimately came down to the twenty kings specifically forming their alliance against Joyboy's faction. If it came down to the WG alliance trying to lead a war against a tyrannical king Davy, then it's hard to believe to present the Luffy analogue as being on the opposite side.