Recent Toy Listing for February & March which also listed the appearance of Ultraman Reiga in Ultraman Taiga the Movie, listed one more item.
This item is a transformation item called New Generation Eye. This New Generation Eye holds the power of all New Generation Heroes.
Well Ultraman Zero & Taiga could be the main Ultraman for this Super Ultraman form. But there is a possibility of them using the power of New Generation Heroes to transform into this form.
Why Zero? It will be the 10th Anniversary of Ultraman Zero since his first appearance in the movie Mega Monster Battle: Ultra Galaxy.