Too small a sample size, and necessarily due to the rules of the Hall, one that's already dated. On the other hand, if you look at recent final fours (excluding ex-first roudners acquired in other ways):
2006: Bears (Benson), Colts (Addai), Patriots (Maroney), Saints (Bush)
2005: Steelers (none), Broncos (none), Seahawks (Alexander), Panthers (Foster)
2004: Patriots (none), Eagles (none), Steelers (none), Falcons (Duckett)
2003: Patriots (none), Panthers (Foster), Eagles (none), Colts (James).
So it does seem important, I guess