Apple - How do I backup and restore my IPA app backups in iTunes 12.7?
This looks reasonably promising - but I don't know how it will work for future releases...
Manually add items from your computer
If you have media on your computer that you can't redownload from the App Store or iTunes Store directly on your iOS device, such as custom ringtones or iOS apps, you can drag and drop the media from your computer to your iOS device using iTunes.
- Connect your device to your computer.
- Open iTunes. Make sure that you have the latest version.
- On your computer, find the item you want to add to your device. If you're looking for Apps, Tones, or Books (for Windows) that previously appeared in your iTunes library, you can find them in your iTunes media folder.
- Drag the item from your computer to your iOS device in the left sidebar of iTunes.
Yesterday (almost a month after my initial question), Apple quietly released iTunes 12.6.3 - a build of iTunes with the same iOS management features as previous builds before iTunes 12.7:
- https://www.theverge.com/2017/10/9/16446572/apple-itunes-12-6-3-app-support
https://support.apple.com/en-gb/HT208079
If you've already installed a newer version of iTunes, you can download this version of iTunes on your Mac, PC 32-bit or PC 64-bit* and run the installer. After installation is complete, you can continue to deploy apps with iTunes.
You won’t be prompted to download new versions of iTunes after you install this version. Learn how to update to the latest version of iTunes when you're ready to upgrade manually.
- Mac
- Windows 32-bit
- Windows 64-bit
So it seems Apple does recognize that their customers need the ability to manage iOS apps from a desktop - but their language implies this is not a long-term solution (i.e. having two separate branches of iTunes). I wonder if they're working on first-class iOS management tool for desktops, like iSync, but for Windows.