It used to mean something specific when an Apple product went out of stock. The old machine sold out right before the new one showed up.

Now things go out of stock because Apple can’t get the chips, or because they’re holding back for a launch they haven’t announced. The HomePod mini has been out of stock almost everywhere for months. I get that there are supply constraints in play, but the HomePod mini?

Then you look at what the Home app picked up this year. Plain-language summaries of camera clips. Multi-camera stitching. 4K recording. These are exactly the kind of features that want a screen on the wall and an assistant you can talk to. They read like software written for hardware that isn’t on sale yet.

It seems Apple has a backlog of devices ready to go, all gated on one thing. A Siri good enough to drive them. A HomePod with a display, a real home hub, whatever the speaker-tablet thing turns out to be. None of it works without an assistant that can actually do something when you ask.

That makes this WWDC the software unlock. Apple shipped the brain first. My money is on the bodies following this fall. September, October, once the new Siri is actually in people’s hands, I’d expect a wave of new devices that suddenly make sense.