This is true. It's a side effect of how we edit data. When you symbolize with unique values, we use those values by default when editing. So for example, if you symbolize based on type of tree, and you have tree type codes of 1, 2 and 3, and you change the legend label to show orange, grapefruit and lemon tree, we will show these values associated with the types you can add when editing the data instead of the tree code number. Thus, the label displays as the attribute value too to match.
The fact that the table is not reflecting this seems like a bug to me. We should probably be consistently displaying the same value. It's unlikely that we'll expose a configuration option for this on the popup configuration.
Thanks
Mike