The director of the Builders series has left Square Enix, so maybe not. There's always a chance though as Builders 2 performed exceptionally in terms of sales; on Steam, DQB2 has outperformed the original DQXI release.

I don't think so because nintendo always stops at 2 of 1 game like super mario galaxy there was only a 1 and a 2 no 3 but i still hope there will be.