If you don't want to read the events like this, here's a timeline
Mario Kart 8 as a series has existed for more than 4 years. Mario Kart 8 came out on May 29, 2014, and Mario Kart 8 Deluxe came out on April 28, 2017. The DLC becamse available in November, 2014. If you purchased the $11.99 bundle, you would have gotten the second pack right on the day of its release in May 2015. The game was first announced at E3 2013, and Mario Kart 8 Deluxe was announced as a trailer in January, 2017, the year before the game would eventually come out.