That's certainly another good idea, but would take a lot of work. In a real offense, your reads may change based on defensive alignment, pass protection called, option routes, tags, etcetera. Plays are built as segments in real life, on both sides of the ball, and in video game form they are distinct entities (which has, imo, always been a shortcoming.)
((You give examples of the west coast structure several times, so I am going to assume you know something of what I am talking about. The west coast offense is as much a common playcall structure as it is identifiable by its other components. ))
Reads are another extension of that. If I'm developing an offensive play, I have coaching points that may give different progressions for a variety of defenses I may see, based on what I would typically face. I could have how many varieties then, based on the same unique play.
With the way Madden does the playcalling structure, that's a lot of coding to be potentially done, given the myriad of variables.