We know the patrons will appear in person in the game, and we know Larian like to tie everything into the plot, and we know the plot does not involve Cthulhu. Who would have shown up in datamining if his name was so much as mentioned.
We 'know' nothing, we expect - as you say yourself here:
They didn't say anything about "choices" outside of the selection of your subclass. So I'm not expecting more than 1 fiend, 1 fey and 1 GOO. And I'm expecting them all to be at around the strong cambion power level.
Not everything is yet datamined.
