No no no no no..... this is happening to fast....
-Are we sure that this is a private server bug, and not a bug that was actually within the scripting of blizzards vanilla back in 2004-2006?
-Gear can have all kinds of enchants, but just like when you shapeshift into Cat or Bear you maintain your +15 agi or +15 str or +mp5 int or whatever enchant you are using, you should benefit from + weapon damage, its still an enchant that provides a bonus, in bear or cat you are using what blizzard calls "natural weapons".
If a warrior gets disarmed in combat for example he doesnt loose his +agi, or + weapon damage even though he is unarmed.
An enchant is an enchant and it should provide a buff regardless of if you are in cat or bear form or you are unarmed. The weapon actually is the gateway that gives you the means of obtaining the enchant.