In order to download iOS updates, users typically need to be connected to a WiFi network and ensure that their phone has sufficient battery. The former is because some iOS updates, especially major ones, are pretty big and downloading it over LTE can take a while, not to mention can eat into data caps.
However, it seems that Apple will allow iPhone 12 owners to download iOS updates over 5G. This change was spotted in a support document in which it seems that there will be a new feature in iOS called Data Mode. This will allow users to set options like to allow more data on 5G, which Apple claims will allow for higher-quality FaceTime video calls, stream higher-definition media content, and also iOS updates.
However, as the support document notes, this setting will not be enabled by default. The default setting is “Standard” which allows for automatic updates (not including iOS updates) and background tasks. This means that if you want to take advantage of the benefits “Allow More Data on 5G” has to offer, you’ll have to turn it on manually.
That being said, we should point out that recent battery tests have found that using 5G on the iPhone 12 could result in 2 hours less battery life compared to LTE, so maybe it might not be something you’ll want to have turned on all the time.