They said OSX dev signatures were only for security, then invalidated one or threatened to based on an iOS business dispute (later backed down after a judge ordered them to).

Similar story with Apple Sign In (though no judge order there).

Steve Jobs incredulously derided both Android phablets ("no one wants these Hummer phones"[1]) and 7"/8" Android tablets ("They are so small, you'll have to file down your fingers to use them"[1]). All the while, Apple was working on both bigger iPhones and smaller iPads. When Apple's version of products were released, those niches weren't terrible, all of a sudden.

1. I'm paraphrasing

Sure but that's hardly Apple promising you to do or not do something and then doing the opposite. Jobs's schtick in these presentations always included talking smack about other products, nobody set their watches by that stuff. What makes it even thinner gruel is that in his lifetime, he was pretty much right - the Android versions of these products were poopy and Apple eventually made better ones. Do you think Job's shittalking in keynotes is actually solid supporting evidence that... Apple is going to turn Macs into iOS devices 9+ years after he died?

Not exactly the same, but it reminded me of how they never made FaceTime an open standard after stating they would.

This is not so much a flip but probably the closest thing to a meaningful 'reversal' compared to the other ones in thread so far. Like, they never said they will never have an App store, styluses are still specialized rather than standard input devices, etc. Obviously, companies both change direction and fail to meet various expectations all the time but 'history of flipping the script' seems pretty tenuous to me, so far.

There's a few more I thought of in this vein, of various sizes:

zfs

java (and also ruby, python) as 'first class' Cocoa languages

GC'ed ObjC runtime

[Ancient history but kinda huge!] just about the entire post-System 7 technology stack and roadmap was tossed.

The behind the scenes story there is that Steve Jobs never actually cleared it with anyone when he announced it on stage, but it turns out FaceTime depended on lots of elements that Apple didn't have the rights to and, therefore, couldn't release into the open without the other rights holders' consent.

The first example I could think of actually counters the OP: when the iPhone launched and developers were told their only option on the platform would be via Web-apps.

Of course Apple did a 180 soon after and introduced the iOS SDK.

Not so sure if that was flipping the script when they were ready or that Apple had hoped to not have to open the OS but bent to the developer outcry (or saw that there might be some merit for growing the platform in opening it up).

Not sure if OP means me, but if so there is a big difference. Going from web app only to a full SDK is opening up the platform, and a big step forward. Going from macOS today, to only allowing apps installed from the app store would be closing the platform and stepping backwards in a huge way.

> Going from web app only to a full SDK is opening up the platform

How is that so? The initial promise with "web apps only" was that they would add the necessary APIs for people to develop web-apps that could do almost anything.

Nowadays Apple (intentionally or not) is crippling the entire web-app ecosystem by not supporting the APIs that everyone else does (no notifications, non-standard manifest, etc.).

IIRC, some guys reverse-engineered the application packaging format and the APIs and were happily hacking away at installing their own apps. This awoke Apple and they created the AppStore.

Other examples of Apple reversing course would be "No stylus on iDevices", no use of intel chips, no switch back to scissor-type keyboards.