Like I said, I'm just speculating and I'd be open to any other explanation that makes more sense.
I do recall that in the past, Apple has been caught by unexpected large demand at a new product release, and their customers got disgruntled about it. Ramping production UP is harder and takes more time than cutting it DOWN. Finding component sources and assembly facilities takes months; slowing build rates can be done in days.
So perhaps -- perhaps -- Apple decided to get ahead of the bulge and have production high enough that they could, for once, cut back and relax rather than have to scramble and hustle with hair on fire. One wouldn't want to lose the opportunity to deliver product to a China-size market if it's there. If it doesn't materialize, one can back off with relatively little pain (by comparison).
But of course, that slowdown action is interpreted as The Sky Is Falling by those who make money when Apple sneezes.
Who knows what's really going down... not I.