A neutral repository _might_ be appropriate for copyrights or patents; it's not appropriate for a trademark, which by definition is not "neutral." It represents the entity from which the services are provided. Even when used by a licensee, the owner/licensor is considered to be the origin of the licensee's goods and services (thus the requirement of active approval and quality control of a licensee's processes and output, as well as the use of their mark).
I'll stick with my earlier suggestion that a group should collaborate to develop a common understanding of the facts, rather than cite certain facts for the purpose of advocacy. I'd also like to identify issues and work together to resolve them, rather than try work through this solely in advocacy mode.
It was in that spirit that I stated that we do not know whether the IETF Trust has the ability to take on the duties of a trademark owner. I did not assert that they lacked that capacity, only that it is an unknown. That said, we cannot rely on an unknown. (I would also note that the IETF Trust is not the IETF; rather it is a trust set up for the benefit of the IETF. To the extent that the Trust is not seen as a legal entity, the trustees (not IETF) would be seen as the owner of the trust's assets.)
I think I've already responded to the other point here (recognizing that the email was a response to Avri), so I'll stop here.
Greg