It looks like Rayman Legends: Definitive Edition will be coming on September 12.
The European Switch shop currently lists the game in the “Coming Soon” section with the release date.
However, no official comment has been made. A demo for the game was briefly available earlier today, but it has now been removed. No date or demo is listed on the US eShop at time of writing.
Until today, Rayman Legends: Definitive Edition was simply listed for 2017. We’ll be sure to update you when we learn more.
The new edition of the 2D platformer for Switch was announced in January this year, and there will be new, multiplayer focused content included in the package.