This is a quite complicated thing...
For one I am on the favouring side to the idea of glamouring the DoH and DoL sets on the DoW and DoM gears.
SE answered something about glamours on the latest letter to the Devs along the lines of:

"There is an image we are trying to take care of in FFXIV, so we won't allow a Mage to glamour in ways to look like a Tank, or the other way around"

Altho the rule of a Mage not looking like a Tank doesn't apply when DoW or DoM glamours DoH or DoL gears, it does kick in if DoH or DoL glamours gears within themselves, which is something that would side-strike be they allowed to be glamoured into other classes.

However they also said something like:

"If there is a specific gear you would like to glamour with, we can do something if you post about it in the forums".

So I see no reason not to ask for them anyway...

Also, about the "Tank not looking like a Mage" thing... Halloween set anyone :v? (I love having my MNK with his pointy hat and his magical star-summoning punches of purification)

On that note, however, does makes me believe that in order to "bypass" their own rule, they will need to create new items for event quests or crafting gears that are clones of the DoH and DoL sets and are for DoM or DoW lvl 1 with no stat bonuses.