The first tigers, the orange bengal could hide new "tiger only" traits.
The second tigers, white and disco, could hide new traits, different from the orange tigers.
The Menagerie Tigers are unique in that they are Exclusive to the Menagerie. Their look makes them unique. They could hide a special trait, but that is more icing on the cake.
Eventually, as with most traits, the tiger traits will be bred out and plentiful. The Tigers however, will not be able to be bred out. So even if your didn't carry a new trait, it still will be unique in it's look.
Hope that clarifies.
