Recaps of the Former Allies

Well as mentioned, only one character from the team is taken to participate as the new team. However, for whatever happened to the others, here's a compilation of what happens to them:

TEAM 1

Shinkenger (P.S: No hard feelings on Goseiger, but since this is written before Goseiger vs Shinkenger, the events of Goseiger vs Shinkenger hadn't happened)
-Ryuunosuke Ikenami: Returned being a Kabuki Actor and would perform in Kyoto
-Mako Shiraishi: Returned to Hawaii to stay with her parents for awhile
-Chiaki Tani: Studied hard at home to get into college
-Kotoha Hanaori: Returned to her village to help her sister
-Genta Umemori: Traveled to France to make a name of himself in the world of cuisine

Turboranger
All of them were in colleges, just like Youhei. However, it's been known that Riki Honoo and Haruna Morikawa are in the same college and are now dating

Goggle Five
-Ken'ichi Akama: Resumed his mountain-climbing and is said to about to climb the mighty mountain of Everest.
-Kanpei Kuroda: Become an esteemed professor in Tokyo University, still passionate on chess
-Saburou Aoyama: About to graduate college and led his hockey team through victories in various competitions, and said once he graduated, he'd pursue his dream of being an inventor.
-Futoshi Kijima: Still worked at the zoo. He's actually offered a lot of better jobs, but he prefers having this kind of humble job

Jetman
-Ryuu Tendou: Still worked with the Sky Force, helping every person in need even without the Birdonic energy. Of course, he's later married to Kaori.
-Kaori Rokumeikan: Accepted her role as the heiress the Rokumeikan Enterprise on her own terms and would soon inherit her family's fortunes (and then marry Ryuu)
-Raita Ooishi: Returned to his life as a farmer and married his childhood friend
-Ako Hayasaka: Became an idol singer and softened up her formerly tomboy attitude.

Changeman
-Hiryuu Tsurugi: Promoted into Commander, effectively replacing Ibuki, and continued to guard peace on Earth in his place.
-Sho Hayate: Became Tsurugi's vice-commander, did his job well despite still womanizing with less success.
-Yuuma Oozora: Retired from the army and opens up a tonkatsu shop, while adopting a new horse named after his previously dead one, Pegasus.
-Mai Tsubasa: Changed division into the intellect one, in order to finally reunite with her lover who departed to space. With Sayaka's help, she became qualified and will go to space soon.

Fiveman
The Fiveman planned to return to Earth and resume being 'Siblings Teacher' in Newtown School... until that 'crash'. While they resume their jobs, they probably are looking for Remi.

Flashman
They're still on their respective home planets.

Liveman
-Jou Oohara: Settled in Midori Town and helped his friend in running her pizza store. Despite being an underachiever, his invention helped them out.
-Megumi Misaki: In memory of Butchy, she became an idol singer. The last time Yuusuke heard of her, she planned to do a charity drive for orphans.
-Tetsuya Yano: Once he graduated, he became a boxer and combined his wit and strength to dominate the ring. Still good hearted, he became a fan-favorite this way.
-Jun'ichi Aikawa: Still on high school. However, he's been scouted to many famous colleges, even overseas

TEAM 2

Maskman
-Kenta: Left the Sugata Racing Team to rejoin his old friend in the Sun Racing Team. Both teams became fast allies thanks to him.
-Akira: Returned to his home village and reunited with his mother. Would soon resume the school he skipped.
-Haruka: Returned to her ninja village. She would soon become the head chief of the village.
-Momoko: Stayed at the Sugata Racing Team to train the new mechanic team. Unfortunately, she witnessed Takeru whisked away with her own eyes.

Dekaranger
With the exception of Banban Akaza, all of them are still working under Doggie Kruger as the SPD Earth Branch. Ban is still on the Fire Squad

Zyuranger
All of them are still in the Heavens with Daizyujin. Though they're probably worried on how long Mei have been down in Earth.

Kakuranger
Still traveling around the Earth as Ninja. Presumably, they still open up their crepe stands as their guises.

Megaranger
All of them are in college, though different ones than the one Chisato entered.

Gekiranger
-Jan Kandou: After Go-onger vs Gekiranger, he resumes to train children on the outside.
-Ran Uzaki: Still an instructor from the inside of SCRTC.
-Retsu Fukami: Assisting Ran in instructing children.
-Gou Fukami: Once again traveled away from SCRTC to better control his wolf side.
-Ken Hisatsu: Helped out SCRTC with his weapon-invention, though still not really serious.
-Rio: Still on his hell of fighting.