This post blew up on Twitter. This post is the update on the old one.
In the San Diego Comic Con (SDCC) 2013, there was a treasure box and in it, there was Ranger Keys and some standing on it. Among the keys were a green Dairanger key (Shishiranger).
Houhouranger at Comic Con 2013 treasure box.
At the Comic Con 2014, the Dairanger appeared once again but in the banners. Also in the background images behind the Ranger Keys on display.
The Houhouranger (Pink Dairanger) Ranger Key even appeared in the Super Mega Cannon promotional photo and appears in the cover art, back and front.@BigMike8109 took this photo of the back of the Super Mega Cannon box.
The Dairanger were first called 'New Powers' and then later 'Squadron' so fans have called them "Squadron Rangers." We still don't know why Johnathan Tzcahor chose Dairanger, Changeman, Flashman, Fiveman and Maskman were chosen to be in Super Megaforce. I do know he is a fan of Sentai and probably wnated to honor the Sentai that came before Zyuranger. Fans call these the 'Pre-Zyu' teams. As for Bandai, I think they just made keys of Zyuranger to Gokaiger, forgetting to skip Dairanger.