In the games I have played, I am 100% certain that the AI is not building work boats, even the lanun. I went into the world builder to check their techs, and most do have fishing. I spread the tech to all of those who did not, but after 100 more turns it still made no difference. I then went into the world builder and placed two falamar-owned work boats over 2 sea resources next to Falamar's capital and watched, and he seems to have disbanded them.
I am now on turn 268 of an epic speed, emperor level game and looking at the world builder, I am the only person with any fishing nets on any sea resources.