Technically they weren't part of the cheat, just needed to start the game. A lot of games at the time also copied the Konami sequence but handled the ending differently.
It was first used in '86 with Gradius, but wasn't popularized until the 90's. Most notably with Contra on the NES, which released only a year after Gradius.
I mean the whole logic of the thread is that if you know one word you can make people think you lived in the 90's. Like, you think some 10 year old born in 2013 couldn't just find some 90's media and say a popular catch phrase?