Brick_clicker on Youtube is reporting that a Collectible Minifigures Series with the set number 71035 is coming in May for $30. This would stray from the norm of Collectible Minifigures featuring one minifigure per blind bag for a fraction of the rumoured price.
The YouTuber also states that the rumoured pack could come with the full range of only six minifigures over 43 pieces for a higher price, similar to what was offered with Bricktober minifigure boxes. They speculate that this possible Collectible Minifigures Series could be exploring the world of Super Mario, with the current course building system only featuring brick-built characters so far.
A LEGO Super Mario Collectible Minifigures Series would be released alongside the theme’s current Character Packs, though the source recognises this in their speculation and suggests that the entire selection being sold as one set would differentiate it enough from the current offering.
Note that the possibility of a LEGO Super Mario Collectible Minifigures Series is only speculation from the source and that these rumours may turn out to be just that, so be sure to take everything you read with caution until the LEGO Group makes an official announcement.