No, it doesn't. Here's the relevant quote, indicating that the only thing they won't cover is damage you cause while attempting a swap. Swapping itself is fine.
WARNING: Apple recommends that you have an Apple-certified technician install replacement drives and memory. Consult the service and support information that came with your computer for information about how to contact Apple for service. If you attempt to install a replacement drive or memory and damage your equipment, such damage is not covered by the limited warranty on your computer.