Hi Dylan,
Welcome to our community! 
On our modern computers, it does not matter whether you use a List or an array for a couple of objects. This course caters to beginners, and the syntax of arrays is easier to remember than the one of List. Rick does not want to overwhelm beginners in programming because many already struggle with putting the curly brackets at the correct position.
If you are familiar with C# and/or other programming languages, feel free to use a List instead.
Has your question been answered?
See also:
- Forum User Guides : How to mark a topic as solved