Nintendo has formally announced that Nintendo Switch Online will launch in September 2018. The paid subscription service will be compatible with games with online components, including Pokkén Tournament DX. More details on Nintendo Switch Online are as follows from company president Tatsumi Kimishima:
Next let’s talk about Nintendo Switch Online, the paid subscription service that expands the online functionality of the Nintendo Switch. We reported previously that the service would launch in 2018, and now the official start time has been set to September 2018. Work is progressing on ways to further heighten the gaming experience for consumers. Details will be made available as they are finalized.