It depends, how good are the Joycons as motion controllers?
Personally I think it still has potential as a IP but it won't be a massive seller. Nintendo also pooched it by doing the free to play/rental experiments when releasing Wii Fit U and the remake of Wii Sports on the Wii U.
The brand can still move forward but they will need to use the Joycons and another accessory (not balance board sized, probably a pedometer that synchs your info to the Switch and a online/mobile app) along with a decent campaign. Can't bank on word of mouth like the Wii era to do the advertising, they need to spend some money to get it to the fitness lovers not following game news.







