I doubt that they are a single app's data. Look at the repeat of certain Device names (try "Abo Mossa") and check their UDIDs - those UDIDs show an incremental pattern in their first 3 digits. This tells me: (a) those devices were bought in bulk and (b) those devices were never sold to one person - since the Device names were unchanged [assumption is that a regular customer cannot own so many devices]. I just don't see how one app (not pre-installed) could be on all the devices bought in bulk by one person and dump all its data to FBI.
The UDID is a SHA1 of a few fields (including a couple MAC addresses): we actually know the exact algorithm; if you are seeing patterns in them it is either a trick your brain is playing on you or a trick the user is playing on you (some people modify their UDID occasionally to keep themselves from being tracked by apps).
At some point, the UDID is being processed by code, so you don't really need to permanently modify anything: you just edit the code that generates it and make that return something different. These kinds of changes are very simple using Substrate, the library we all use (that I developed) for changing code at runtime. For the UDID, the obvious candidates are "edit every app so [UIDrvice uniqueIdentifier] returns fake" and "edit lockdownd so it calculates the wrong value every time it is generated".