Redbox sent me an email that had a picture of RDR2 "Disc 1" in the list of new games. I wasn't sure what that meant, and figured that data disc might have had a gimped version of the game with only one or two chapters.

Turns out, you have to rent both discs to play! One to install (which took like two hours for me, if not more), and one to play. I guess you only need to rent one disc after that, but they're still getting at least $6 out of anybody that wants to play.