What if ddr4 Termination is done at last word component
As long as the termination resistors are placed at the locations recommended by the memory chip manufacturer you should be good. 


Any series terminations should be placed close to the driver chip. 
Any VTT type terminations should be placed at the end of the signal trace lines.
Any differential signal terminations are generally placed between the two signals of the differential pair at the extremity of the pair. 


Keep in mind that it is the circuit signalling topology that is important to maintain signal integrity. The order of chips in the bussing is not material to the the signal integrity.