I'm curious about your post, but not clear about what you're asking. I generally prefer to manage updates myself. That is, get notified there is an update available and then decide if I want it.
From what I understand about how it works for me now, I can see there is an update(s) available while I am using my iOS device(s). I can then choose to update or not, selecting "update all" or just one or more. Once done, the app is updated I can then go on about using the device.
Separately, I can choose to update apps with iTunes on my iMac. I log in, check updates and if any are shown, choose to update in the iMac. This means the next time I sync to the iMac, the apps which were updated on the iMac will get automatically updated on the iOS devices.
I read somewhere that the process had been changed. In the past, when I updated on the iOS device, this would be communicated to the iMac, in effect, sharing the updated app to the iMac. Now, they are treated separately. That is what I understand.
For example, I am updating three apps right now on my iMac using iTUnes. One of them is 620 MB (Monument Valley). I prefer to update this large file on the iMac rather than on the iOS device. I can start the update on the iMac and just forget about it, even using the app if I want rather than wait while it loads.
I don't know if there is a way that any of this happen automatically. That is, the apps just get updated in the background.