On the official Nintendo YouTube channel, Nintendo have seemingly made a big mistake in their video description for Super Dragon Ball Heroes World Mission!
The description of the video reads:
The time has come to summon legendary warriors from different universes… Announcing SUPER DRAGON BALL HEROES: WORLD MISSION, an action-adventure Dragon Ball card game coming to Nintendo Switch & Steam on April 5, 2019!
You can check out the video this occurs in here:
The trailer itself has no mention of Steam so it was clear that this was likely copy and pasted from a description that Bandai Namco provided Nintendo.
This is likely to be a human error as Nintendo has never really promoted any other platforms other their own in the past when uploading trailers to their social media pages so it could be corrected quickly.
If we have any more information to share we will cover it here at NintendoSoup so stay tuned for more!