'Will' is sometimes used to add emphasis. I've looked through the dictionary at all the meanings and can't quite decide which one is being used in this case, but it is quite common. Often used to express a lack of sympathy, a sort of 'well if you choose to do that, what did you expect to be the result' meaning.
It is often part of a parents' repertoire
Kid: Mum! The dog just bit me...
Mum: (in an exasperated voice)Well what do you expect. You will keep poking him!
The mother doesn't mean that the child will poke the dog in the future. She means 'it's your own fault'.
So the original could be re-phrased: You choose to drink that much so of course you will fall unconsious.