A theory I am working on...
Not really a theory so much as a Type. Christ said that the whole of Scriptures testifies of Him. Now that is certainly true of the OT as it was in existence at the time. Logically that statement can be extended to the NT also, as Christ new what would be put in there long before He came in the flesh. (One could argue against the inclusion of the NT in that statement tho.)
As you know there are many "Types" in the Scriptures, which are basically foreshadows of future events. My thoughts while at work this past morning were on the wedding Christ attended shortly after being baptized. The whole "My time is not yet come" and turning the water into wine. Not just wine, but that which is much better than was originally given.
My initial thoughts on this, tho more study is needed, is the wine is a type of the covenant, possibly Mary as an obedient Jew, and the guests as the Jews & Gentiles stating this covenant is better than the old.