I think that Lin Manuel Miranda wanted to emphasize the “blackness” or darkness of the plot he plans to hatch. Since most English speakers are familiar with the proverbial idiom “The pot calling the kettle black,” they are able to fill in the blanks in Hamilton’s words and understand that his plot is exceptionally “black” or dark/twisted/revolutionary/cunning/etc. Of course, it also fits in with the rhythm and meter of the song and provides a good transition to the next few lines. I don’t think Miranda is referring to any pot or kettle of historic significance, just the idiom “The pot calling the kettle black.” More information: https://en.m.wikipedia.org/wiki/The_pot_calling_the_kettle_black https://english.stackexchange.com/questions/127144/the-meaning-of-the-english-idiom-pot-calling-the-kettle-black