It's more of Toei, the company that finances and distributes the sentai series being scared by Go-busters dismal performance.
The show and toys sales.
So they fell back to a tried and true theme;
Kid's love dinosaurs. They'll love them even more because their bright and colorful.
Profits should be fine next year. Better than this year's that's for sure.
Rough translation of the story blurb
-In Ancient Times, the age of the dinosaurs, Earth was invaded by an enemy from outer space. The only warriors capable of fighting off this threat were the "Kyouki Ryu no Sha", abbreviated as "Kyouryuger."
In modern day, the Kyoryuger return to fight (I can't make out if it's the latest generation, or Zyuranger-esque ancient people awakening now to fight.) They use the powers of Dinosaurs through the JyuDenChi, and are partnered with the giant mecha, JyuDenRyu.