Fury doesn't deserve faith... He has a history of conning the public and saying he'll do X then ends up doing Y. How he manages to never get held accountable is rather impressive.
I'm not so convinced those in Saudi are willing to pay big for Fury vs Usyk. Even if it is for the undisputed, Fury isn't much of a draw by himself and he knows Usyk is going to be a very hard nights work for very little commercial gain. He knows his best chance of a payday is against Joshua and there is no better time to try and fight Joshua now whilst his confidence is at rock bottom and he is coming off back-to-back losses. Even with his losses AJ is still the money man in the division and Fury knows this is a good chance at his biggest payday.
For the sport. I'd rather this fight didn't happen and Usyk vs Fury goes ahead for undisputed. For myself I'd love to see AJ spark Fury out (a position I've always held) but ultimately that puts a bit of a dampener on the division as it just means it's Usyk vs Joshua 3 for undisputed and Usyk may as well just call himself undisputed as he has Joshua's number.