You'll be able to try out the 30 person exploration whether you're paid up for NSO or not.
After a series of indie releases earlier today, Nintendo has dropped a new trailer for their next retail release alongside a special promo.
Nintendo have posted an "overview" trailer for the May 2-launching Endless Ocean: Luminous, and have also confirmed that the game will come with a 7 day trial code for Nintendo Switch Online (the basic plan). This is presumably so anyone can take advantage of the 30 person online exploration option announced alongside the game in February.
The trailer is below:
