This is a simple fix.
From now on all bout agreements will state:
All CHAMPIONS must agree to fight any top 10 opponent if their original opponent has to pull out with in X amount of days prior to said name bout.
Of course this can easily be extended to all main event bouts.
Then the question would be:
Of the top 10 fighters, who is willing to fight?
Of those who step up, the CHAMP would then get to choose his opponent.
Done, no more drama.
Your welcome! 
'Top 10' would be the sticking point.
Yes, top 10 may be a hard sell. However, who could disagree that a top 10 does not deserve the shot?
Besides, what top ten LHW is not begging for this fight right now?
Also, all the advantage goes to the man with the scheduled fight. For he is in fight shape.
He didn't turn down a fight with a Top 10 Contender. He turned down a fight with a guy from another division.
Authority Figure - He didn't turn down a fight with a Top 10 Contender. He turned down a fight with a guy from another division.
This
I fully understand Sonnen is not a top 10 LHW.
I am commenting on an acceptable way to prevent this from happening in the future.
Do you agree with plan or disagree and why?
I would rather of heard the top 10 LHW were offered the fight. Jones then accepted the fight with Gustoffenson.
They would have to have an official ranking system.
The only reason Sonnen is a good fight is because of your "hype emotions", what Dana just told you to think. Not who deserves it.
Any top 10 can be easily explained.
The Sonnen bout is being sold to sell tickets.
Not advance the division.
What's better?
Use the current associated reporters ranking system.
Have fighters agree to the top 10 when signing agreement.
Done.
Agree with OP, we don't have to get into specifics about who is top 10 or not. There should be something in the contract about an agreement to fight a suitable replacement, even if only 2 or 3 guys are mentioned, and the fighter should be willing to fight them on a day's notice if need be. Amazing we've come this far in the sport, seen so many unfortunate cancelations of fights, and they still haven't nipped this in the bud. I guess in the past we just relied on the fighter's warrior spirit and their loyalty to the sport and their fans. Not anymore.
wisdomseeker76 - Yes, top 10 may be a hard sell. However, who could disagree that a top 10 does not deserve the shot?
Dude, sonnen wasn't even in his division. Even your new contract would've been hard to enforce in this situation.
wisdomseeker76 -I fully understand Sonnen is not a top 10 LHW.
I am commenting on an acceptable way to prevent this from happening in the future.
Do you agree with plan or disagree and why?
How would your idea prevent this from happening in the future if it would not have forced Jones to fight the only guy willing to fight him in this case?
I know for a fact, there will always be a hungry top 10 willing to fight within 24 hours.
If not, cancel the bout. No problems.