If you don't want to sign the CA, https://www.python.org/psf/contrib/, and upload a file without a guarantee, which is never given ;-), just give the patch in a text message.  While it may be unreasonable to *expect* 2to3 to handle this, it also might not be unreasonable for it to do so.  It would be especially useful if one were converting to Py3 and not planning to maintain the 2.x code.

My concern is that this might be one of multiple similar situations, so that patching just one might not be all that helpful.  But I have not looked at the list of fixers to determine is other are affected.