I am in the process of slowly converting my cars to Kadee's. On most of the Lionel conversions I pitch the claw coupler since you have to cut the truck assembly to remove the claw thus no way to reinstall.
On the MTH trucks, I have been able to remove the claw assembly without damaging the truck. So in theory someone "could" reinstall the claw in the future. I don't know how the Chinese build these trucks, but I have never figured out how to reinstall the claw without completely disassembling the truck. That is a PITA!! I don't think anyone would try try that. So - keep the claw - or pitch it. Thanks