[rkomorn]

I'm guessing any/some/all of:

- Whether parent company has the capacity to service your plane at the landing location

- Whether parent company has the capacity to handle boarding new passengers for the next flight at landing location

- Whether parent company can get next flight off the ground from landing location

- "Risk" management by sending planes and passengers where parent company thinks it has better ability to recover to normal operations

- And probably a bunch more only people who work in that industry would think of