I think the reason Dean makes a Rent reference is to validate the obvious parallels between the “Carry On Wayward Son” and “Seasons of Love” scenes. “Seasons of Love” is a song about measuring the time that’s passed in your life by the amount of love you’ve given and received. Love letter to fans, eh? Damn right.
(It’s also maybe sorta noteworthy that Rent follows the love story of a queer couple and one of them is named Angel but what do I know)