Command block minecarts still show pre-snapshot GUI

Whenever I use a CMD block minecart in the snapshots, It has the updated texture but still shows the old GUI from before the snapshots.

I expected the new, fancy GUI to show up(command block types, other boolean options) when I right clicked a CMD block minecart in the snapshots, but instead the old GUI appeared from 1.8.8 and before. This annoys me.

1.Get a CMD block minecart.

2. Right click on it.

3. Observe its pre-snapshot GUI.