Join up to 38 million players, so crossplay confirmed.
http://www.nintendoworldreport.com/news/48335/warframe-to-invade-switch-november-20
The alien invasion of the Switch will be landing in November.
Warframe, the free to play shooter announced for Switch in July, has confirmed a release date of November 20. The game offers play with "over 38 million players", indicating that crossplay will be available for the game.