I think it depends more on the ballet than the choreographer.
Some ballets will never be the same without the originator of the role. Others will.
SFB has a new ballet called "Chi-Lin" choreographed by Helgi Tomasson. The role was created on Yuan-Yuan Tan, and I wonder if anyone but her will be able to do it with the right East/West nuances essential for the role.
Conversely, all the roles in "Prism", which is also quite new, could be done by anyone in the company.