“If the Unreal Editor didn’t change my data when I didn’t tell it to, I wouldn’t have to rely on source control to protect me.”
The problem with that is that the only time you’re experiencing this issue is when you have told the editor to do so by hitting the asset-specific Save button since the Save All button wouldn’t save anything that hasn’t been edited.
I have brought this to the appropriate team as I wouldn’t feel comfortable making claims without making sure and their response was that we would like to keep this functionality.
Hopefully, even if it isn’t a prompt asking to check the asset out, a feature to prompt for confirmation can be added, even if it is an optional prompt that is enabled. If you would like to keep track of this, while we do officially support the Github source control plugin, it is developed by a member of our community and I’ve made him aware of this here (Please be aware that you may need to be signed into Github or this may 404.)