As near as I can tell, he took his wife's birthday off: I saw something earlier about him throwing Ayesha a surprise party for her thirtieth birthday, which happens to be today.
Seems odd that they scratched Curry and Livingston on the same day, though: they essentially played tonight without a point guard. And they're probably going to sit Cousins, Iguodala and Thompson and/or Durant against the Pistons, tomorrow.