Ok,  I think I understand what you mean.  I went ahead and deprecated everything;  the comments suggest that maybe the intention was to not deprecate it until GHC 7.10,  but honestly I don't think anybody's using the new builder yet and I think we should nuke it from orbit,  now,  and not encourage any uptake of the builder included with GHC 7.6.    And it's not like fixing this is hard.