Hi,
Don't know if this is assistance or not.
The following are links to the service manual.
This one shows the Bluetooth module that they have listed for this laptop. It states that it 'features' a mini USB interface. So perhaps the BIOS has been setup to connect a USB module to the Bluetooth Interface chipset and not a PCI-e connection. I don't know, this is pure speculation on my part.
http://www.manualslib.com/manual/232592/Acer-Aspire-7560.html?page=48#manual
This link shows where it is located.
http://www.manualslib.com/manual/232592/Acer-Aspire-7560.html?page=128#manual
This one shows what you already know - the WiFi card location.
http://www.manualslib.com/manual/232592/Acer-Aspire-7560.html?page=108#manual