This issue did not occur on Windows at the same CL.
This was originally being tracked by [Link Removed] but after initially testing the fix for that JIRA, this particular issue persisted and it was determined they are separate issues.
1. Create a new project (I used BP) on Mac
2. Select File > Package > iOS
3. Install the app to the device
RESULT: The icon is a placeholder
EXPECTED: The UE4 logo default fallback icon we package with the editor
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-53492 in the post.