You'll face some difficulties to explain a DDR RAM design in terms impedance matched transmission lines, although it's based on the principle, of course. You'll find e.g. an application note suggestion (from Micron TN4607:Transmission line that is not properly terminated will experience reflection, which will attenuate and/or distort the transmitted signal to the receiver side, leading to read error. Controlled impedance of trace and terminating resistors are needed for this case.
The statement may be read as other words for "they should be place elsewhere, but it's not practical". But even a misplaced series resistor can help to reduce reflections in a mismatched transmission line. DDR RAM design is mostly a compromise.Location: The series resistors should be located near the first DIMM for ease of routing.