This draft is reasonable and OK in all material aspects.

The document has no security considerations and that is well motivated for this document.

I just have a few general comments and nits:

1) 
Section 2 first paragraph. I think the sentence is missing an "is" word. Assuming that the sentence intended to say:
"... whose registration policy is changed from IETF Review to Expert Review."


2)
I'm not convinced that it is suitable and particularly useful to include a mail discussion as a reference to a standards document. At least in this case when the discussion seems to be in agreement at large with the initial statement by Sean Turner. Even though this was interesting reading for me, I think a summary of the strongest arguments would serve the document better than a link to the actual discussion. In fact, the initial argument by Sean seems to say most of what is relevant.