I agree that you can't do that completely and that the majority of the specific stuff does sound cool but like you said, after the first time, I don't really want to hear it again. I don't really mind hearing it again, as long as it's relevant. I look at the QB intros most specifically. Last year, Matt Cassel's intro was: "Once a draft-pick in Major League Baseball and a long time back up to Tom Brady, here is quarterback Matt Cassel." "How about this, he wasn't good enough to play in college, but he's good enough to play in the pro's. Pro Bowl quarterback, Matt Cassel."
That sounds great for play now but in a franchise, I honestly don't want to hear it after about one game. I could live with it in the initial preseason opener or something but I feel like if you're playing franchise, their will always be several things more relevant to the incoming game than his career path. If I'm in Week 4 and he just threw 4 interceptions last week and lost, I'd rather hear about the rough game he had last we with an overlay of his last week's stats rather than his season totals. Same goes for a great game. If he's having a great season, I want to hear about how he might be on his way to a Pro Bowl birth while they show his season stats.
It lacks some specificity but creates immersion, which is the most vital part of a franchise/career mode. It makes you feel like Jim & Phil watched the other games over the week and did their homework. It also creates a multitude of situations that can be applied to any player over a long period of time, and still give off a 'fresh' feel because of it's relevancy to the current franchise.