These figures are all hypothetical as its not been done yet. When a good mapper is able to put it on the rollers, we can start to see how the engine and gearbox performs. the gearbox 'may' need a remap also to utilise the power delivery, but I am confident someone like Celtic Tuning would be able to produce smoother results than Mazda's map.
I'm confident in Mazdas in engineering that it will cope with the small increase in power..but as ever with new cars and new engines/boxes, the leaders will learn the lessons first so that the followers can tread more carefully
Mazda also come from a 'tuning' history with their cars from the MPS subsection and the MX5 and RX7 and RX8, they wont just make something that can only cope with the 'issued' amount of power as they know people tune their cars, its been a big part of their history.
Does the PHEV not use the same gearbox?