Perhaps a fusion class is intended to work this way. If one adheres to the proper techniques of doing Taichi, Yoga and Pilates, breathing control may turn out to be beyond imagination. Should one breathe naturally, adopt reverse breathing, follow yogic abdominal breathing or lateral breathing for pilates ?
Based on my current understanding through reading up, all mind body spirit practices follow the same pathway in terms of energy circulation. ie the microcosmic orbit which involves the circulation of energy around the female yin and the male yang pathways. The abdomen, or area around the navel, is believed to be the starting point of the pathways.
The yang path travels from the abdomen down to the perineum and back toward the coccyx region. From here, the path continues up the spine, up and over the top of the head, and onto the face. Yang then moves down the face, into the mouth, and ends at the palate. Yin begins in the abdomen and travels up the medial front line of the body, ending at the tip of the tongue. Based on this distinct path, there is really no difference in energy flow between Yoga and Taichi in my opinion.
Whether this is proven true or not, only time will tell...