It was just Saban's thing, but like I said, sometimes it's hard to tell if you haven't seen both shows. This one is a bit stranger, but not impossible. TMNT has not only been shown in Japan, they had an exclusive spinoff series of the 1987 show, which coincidentally borrowed a lot of elements from Super Sentai.
There's more than just the Rad Bug, there are a lot of other things that you'd think were Saban's or Disney's creations because they're stupid or weird, or that you'd think are Toei's because they're dark.
Hamster sensei in Ninja Storm? Hurricaneger had it first.
Pink dying in Lost Galaxy? Not in Gingaman.
The giant talking dog in SPD named Doggie? Not only was it Dekaranger's idea, the suit looked even more ridiculous.
Old guy dying in Jungle Fury, and several other dead masters? Not only were those Disney's ideas, they replaced the decidedly more family-friendly mascot suit kenseis of Gekiranger.
The list goes on.