Seems more likely to me then them deciding to take a sizable loss on inference by dropping prices by 80% for no reason.
Optimizing serving isn't unlikely: all of the big AI vendors keep finding new efficiencies, it's been an ongoing trend over the past two years.
This is my sense as well. You dont drop 80% on a random Tuesday based on scale, you do it with an explicit goal to get market share at the expense of $$.