I've been part of the GNU Classpath community for many, many years (I write JamVM) so I'm well aware of the GNU Classpath exception that Sun adopted when releasing OpenJDK.
I agree, distributing a source file derived from a decompiled class file complicates things. However, you are being extremely disingenuous quoting the Classpath exception. The intention of the exception is to enable software to be used with OpenJDK/GNU Classpath without it becoming subject to the GPL itself (in a similar way to the LGPL).
"As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent modules,
and to copy and distribute the resulting executable under terms of your
choice, provided that you also meet, for each linked independent module,
the terms and conditions of the license of that module. An independent
module is a module which is not derived from or based on this library. If
you modify this library, you may extend this exception to your version of
the library, but you are not obligated to do so. If you do not wish to do
so, delete this exception statement from your version."
In no way is the decompiled class file an executable, and in no way is decompiling linking to produce an executable.