Oh, duh, now I get it. That's very annoying.
In principle, you could rename the classes on the class-file level after compilation, back to the original names. That wouldn’t violate the license.
Moreover, under the following definition in the license:
`Modification' of a file
means any procedure that produces a derivative file under any
applicable law -- that is, a file containing the original file or
a significant portion of it, either verbatim or with modifications
and/or translated into another language.
…compilation would count as modification (“translated into another language”), and compilation also changes the file name (from .java to .class), so distributing the compilation output should be fine. Furthermore, any changes to the sources can be distributed as a diff patch, which also has a different file name.
So, the workaround can be quite impactful in the end. Renaming the entirety of the code base, potentially.