You are getting excited for nothing, because, as usual, context eludes you.
The story starts with 3 words - Wealth, Fame and Power.
Those words are the trigger of the story.
Oda proceeds to call Nami, Luffy and Zoro as triggers.
The "for now" doesn't refer to triggers but to something else, he was asked to draw more and he shortened it to just those 3.
Did you really think you would fit more than 3 people among Strawhats into triggers?