I mean it can change but how long did it take? They were a force in the 30's and 40's with their last anything in 1960. So yeah, 50-60 years of complete and utter futility can get anyone kicked off the list. A team like Clemson with some more sustained success could replace a team that does squat for 40+ years.
I also think historical reference can aid a team's claim. It's been awhile for Michigan and Notre Dame but I just don't see them ever losing blue bloods status. I kind of feel the same about Nebraska but I may be biased. I guess the length of a team's reign and their dominance within it may buy more time.
And I have no concerns when it comes to Nebraska. We'll be a force again before we ever get remotely close to losing BB status. Yeah these last 15 years have been rough but it won't be long now.