Remember that Steve stated that worker consumption only refers to workers that would need seperate life-support infrastructure. With that in mind, the logical conclusion is that even if there are civilian teachers/cooks/cleaners/maintenance workers/etc. they are being housed in the Academy itself and supported as part of the upkeep cost of the Academy. An Academy simply does not need an extensive civilian population living around it to perform supporting work for it to function, which is different than 'Has no workers'.
The only place this abstraction falls apart is in the case where a race has 0 total population (where is the Academy pulling its people from?) but in such a case, wealth shortages would probably sink you anyway so who cares? Its a sufficiently edge case not to matter too much in the grand scheme of things.
If we want to be technical about it, an Academy WOULD need a population accessable by trade route. And while having a new trade good "Students" could be funny, I dont think it would add much to the game.