100B contractual definition of AGI actually makes sense. If AGI is a system that surpasses human in all economic activities (as per open ai own definition) then you should be replacing many markets and easily reaching to the 100B revenue. 

This also is a way to measure how fast compared to competitors you are getting there. 

So it’s very fair and clever way to identify contractually you made the goal and you did it first than most of the competitors; imposed by your own definition of AGI.