False.
"While you cannot use a tie-in sales provision, your warranty need not cover use of replacement parts, repairs, or maintenance that is inappropriate for your product. The following is an example of a permissible provision that excludes coverage of such things.
While necessary maintenance or repairs on your AudioMundo Stereo System can be performed by any company, we recommend that you use only authorized AudioMundo dealers. Improper or incorrectly performed maintenance or repair voids this warranty.
Although tie-in sales provisions generally are not allowed, you can include such a provision in your warranty if you can demonstrate to the satisfaction of the FTC that your product will not work properly without a specified item or service. If you believe that this is the case, you should contact the warranty staff of the FTC's Bureau of Consumer Protection for information on how to apply for a waiver of the tie-in sales prohibition."
Source: http://www.mlmlaw.com/library/guides/ftc/warranties/undermag.htm
Apple goes far beyond this. They don't merely recomment that you use only authorized repair centers, they will actively disable the entire product if it detects one OEM part was changed for another identical OEM part.