Not very popular? That is not even remotely accurate.
Anyway, yes, they will finish the team.
1. DaiRanger WAS popular in Japan.
2. They spent this money to make a body for RyuuRanger, they are going to utilize it and make the rest of the team since 3 of the 4 remaining rangers are male and they only need to make a new helmet and one new weapon (or rather, the top of the weapon).
3. It just takes time since Bandai seems to release rangers at the slowest pace possible. They still have to finish Jetman, who have been for over a year now. Look at how long it took them just to get to BoukenBlue and Black and is taking them to even get to the other half of the ZyuRangers.