Except Toady has never said clearly either way. I may be mistaken, but I did some digging to try and find a definitive answer and that resulted in my first post in this thread.
Even if Toady had said either way a discussion wouldn't be unreasonable. Admittedly this debate has happened a number of times. I'd be surprised if there are any, but new points should be added to one of those threads.
In the quote I remember about this Toady said something along the lines of it could work, but he doesn't want to add any more breaks or actions to dwarves that get in the way of their work. They already spend ages wandering off to eat, drink, sleep, party etc.
I want sewage in for lots of reasons but he's right, the core gameplay of how dwarves make decisions would need to be overhauled. It could already do with something, like a dwarf knowing he'll be in the mines all day so he should take a packed lunch, or realising he doesn't need to go back to his own bed right now and can use a nearby bunk instead. I think people then suggested just doing it right after eating or something so we can have toilets near dining rooms.
I'm annoyed I can't find the quote, it was a transcript of something. Maybe a DFTalk or maybe an external interview.
He may have changed his mind since then.
But anyway, the point about action selection in dwarves is probably worth a suggestion thread of its own if we don't have one.