It's good comedy, but the fact remains that it's buried somewhere in the employee conduct section not to place the company in a unfavorable fashion.
Repeating the management letter verbatim was probably the biggest mistake...
His movie trailer for Aluminum Lady is far funnier, and probably something AA can't really touch because it isn't using an AA logo, nor is it repeating an internal memo verbatim.
More importantly... I saw a few references in the comments on one of the referring websites to free speech...
The right to free speech is pretty limited, in that only the government can't retaliate against you for what you say about it.
Anyone else can (and will) retaliate, especially if there's a code of conduct similar to what AA has in place. AA didn't have a social media policy in place when I was there, but I do know that the "portray the company in a negative fashion" line was used on several people at different times.
You can be a whistleblower under certain circumstances and done thru the appropriate channels, but posting a YouTube video is a much different argument to defend.