Nintendo has announced that from July 29th, 2020 until August 4th, 2020, Pokkén Tournament DX will have a free game trial for Nintendo Switch Online subscribers. It will be available for subscribers in Japan as well from July 27th, 2020 until August 2nd, 2020. The game will also be available to purchase with a 30% discount on the Nintendo Switch eShop in Japan from July 27th, 2020 until August 9th, 2020 while the sale will be available in North America and Europe from July 29th, 2020 until August 11th, 2020.

Sources: https://twitter.com/NintendoAmerica/status/1285999620426956800 and https://twitter.com/Nintendo/status/1285835131618422784