The tech specs actually state "Bluetooth 4.0-enabled Mac computer", which your machine most definitely is not. Your 2009 iMac does NOT have Bluetooth 4.0 hardware.
Regardless of what version of the driver OS X ships with, your iMac has Bluetooth 2.1+EDR. It does not support Bluetooth 4.0.
I agree with you, BUT as I noted the tech at Apple checked and as long as the iMac is running Apple's Bluetooth software above 4.0 then it will work. As I said I have a 2009 iMac and am running Apple Bluetooth Software Version: 4.3 (Yosemite) and it paired, pointed and highlighted but wasn't fully recognized. Now I have upgraded to El Capitan and I have version 4.4.014 16320 and the Trackpad 2 is working fine. The hardware of course remains the same Bluetooth 2.1+EDR.
So in summary:
1) Apple released Force Touch under Yosemite (updated MacBook this year), but when they released the updated Trackpad 2 for both new and older Macs it doesn't work under Yosemite only under El Capitan
2) Specs for Trackpad 2 clearly state it requires "Bluetooth 4.0-enabled Mac computer", but it will work as long as the Apple Bluetooth Software is v4.0 and above (but really it only work if it is v4.4 running El Capitan)
I hope that you can see that this is a very confusing situation and Apple should clarify this better.
Comments
The tech specs actually state "Bluetooth 4.0-enabled Mac computer", which your machine most definitely is not. Your 2009 iMac does NOT have Bluetooth 4.0 hardware.
Regardless of what version of the driver OS X ships with, your iMac has Bluetooth 2.1+EDR. It does not support Bluetooth 4.0.
I agree with you, BUT as I noted the tech at Apple checked and as long as the iMac is running Apple's Bluetooth software above 4.0 then it will work. As I said I have a 2009 iMac and am running Apple Bluetooth Software Version: 4.3 (Yosemite) and it paired, pointed and highlighted but wasn't fully recognized. Now I have upgraded to El Capitan and I have version 4.4.014 16320 and the Trackpad 2 is working fine. The hardware of course remains the same Bluetooth 2.1+EDR.
So in summary:
1) Apple released Force Touch under Yosemite (updated MacBook this year), but when they released the updated Trackpad 2 for both new and older Macs it doesn't work under Yosemite only under El Capitan
2) Specs for Trackpad 2 clearly state it requires "Bluetooth 4.0-enabled Mac computer", but it will work as long as the Apple Bluetooth Software is v4.0 and above (but really it only work if it is v4.4 running El Capitan)
I hope that you can see that this is a very confusing situation and Apple should clarify this better.
I agree. That IS a bit of a mess.