Uh... I'm sure one of them could be by to answer you directly, but the
GSL is very clear on this already. No, people cannot make those under the
GSL. Whether the "fan site policy" will be more lenient for fan-created and/or not-for-profit software, we'll have to wait and see.
That being said... operating under US copyright laws with
really good legal advice, you
might be able to bypass the
GSL entirely and create unlicensed character generator software.
You may not like that answer, but the
GSL already has a straightforward answer, and that answer is "No, you can't."