In the past, things like this used to be done for signing certificate rollovers.

hmm, my money is on some actively used 0-day exploit that Apple is sealing shut before the CVE gets announced.

By the looks of the app list, they seem to be apps and games that used to be popular and have fallen in disrepair and apps that are starved of maintenance attention.

On the one hand it could be an exceptionally good example of "stewardship"; on the other hand, if this is true, what if authorities could later compel Apple to manipulate applications in some malign manner?

I saw this the other day in a couple of apps, I've checked other apps and didn't have that, did a quick check on HN frontpage and saw nothing and said wth I'll update to see if something changes in the app or there is a message. Got nothing, and didn't think more about it but I'm not sure why, is it the "trust in the process" thing or what?

Neither developers nor consumers should be comfortable with this, as this breaks the trust model and is extremely worrying. The site is of course downplaying it given its name, which is a huge shame.

Vast majority of change logs are along the lines of “implements to make things better”

Speculation for fun: I always thought popular apps can use private apis or are handled in a special way by the OS itself. If yes, perhaps this is related.

Then again I found no source for that - and some certificate rollover seems more likely.

Could be a fix for per-device asset optimization that got messed up somehow.

This sounds like a bug with the App Store app than a new update actually being installed.

Is it a conspiracy, or just a bug in the app store? Nobody knows.