It is virtually impossible to look at a patch number and advise what functionality you would have to test to see if it is broken after patching. There are 84 bug numbers in the readme and every installation is different meaning what versions of the patched code you already have in place. You can open Oracle Applications Manager in System Administrator and view the patches applied and click on that patch number, then details then files copied to get an idea of which files were replaced.
Other than that, here are the notes that discuss this patch. It appears to be mostly around copy and concurrent request processesing.
Scheduled Request Goes Inactive/On Hold Status Automatically by Concurrent Manager User (Doc ID 737282.1)
Concurrent Manager Has Put The Concurrent Request On Hold all of Sudden (Doc ID 2034116.1)
12.2 Concurrent Submit Request > Copy functionality related issues ; Does Not List Child Requests Failing With FRM-41072 (Doc ID 2040287.1)