system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Mace Windu is the one sent after General Grievous, and so Obi Wan is the one Anakin tells that Palpatine is Darth Sidious. How do things change?
gpt
If Windu and Kenobi switch roles, Palpatine does not yet reveal himself as the Sith Lord.  Palpatine knew that Kenobi was both the best chance of keeping Skywalker in the light and the most likely to defeat Grievous (the final obstacle to the war).  Palpatine wouldn’t try to finalize his corruption of Skywalker while Kenobi was on Coruscant and still had time to talk him down.