Why would Disney Channel go off the air? Is there a reason why it would go off the air?
There was not enough original programming to keep it afloat. This statement is made even worse with the fact that Phineas and Ferb is on Nickelodeon in this timeline and had already ended it's run by this point. Most of the original programming was preschool shows, which were not the main focus of Disney Channel, forcing it into closure.
Most of the international feeds were shuttered in 2009, with six feeds lasting past January 1, 2010:
Disney Channel UK closed on February 5, 2010.
Disney Channel Australia closed on April 30, 2010,
Disney Channel Brazil closed on October 23, 2009.
Disney Channel in LATAM closed on March 19, 2010.
Disney Channel France closed on November 13, 2009.
Disney Channel Italy closed on January 15, 2010.
Disney Channel Germany closed on August 21, 2009.
Disney Channel Japan closed on February 26, 2010.
Disney Channel Spain closed on April 9, 2010, ending the channel's presence in Europe.
Disney Channel Portugal closed on December 25, 2009.
Disney Channel in Scandinavia closed on May 22, 2009, starting the worldwide closure.
Disney Channel Poland closed on July 3, 2009.
Disney Channel Turkey closed on December 4, 2009.
And none of these feeds had ever aired Fairly OddParents, because seasons 1-4 weren't sold to Nelvana.