Is it possible to use iTunes Match to replace my existing metadata with metadata from the iTunes Store?
No - the design clearly is intended to honor whatever set of metadata you have currently entered into your library. As you have discovered, the matching process can find songs based on other criteria and re-downloading the "canonical" AAC 256 kbps stereo will not currently fill in any metadata holes or correct parts of the metadata that do not match what Apple has in the store (or it's Match database for songs that are not for sale like the AC/DC catalog)

I can see two reasons for this:


Intentional - preserve user customization where the data may be better on the individual customer iTunes database.
Not automating the process of cleaning up songs that may have been passed or downloaded rather than ripped when connected to a metadata lookup server or otherwise encoded by the official artist when it was sold or released.


I specifically have hundreds of Hawaiian songs where I've entered the metadata with the help of a native speaker to have the correct punctuation (and that doesn't match Apple's punctuation). There certainly is a great need for a tool to help people manage this, but iTunes Match isn't that tool today.