I think he means terminating the signal from the node or the newer switch that goes to the potential joeys you wouldn’t need on your system.
That's how I read it as well. Coaxial cable at these frequencies is a transmission line, and any change in impedance will cause reflections of the signal back up the cable, and attenuation down line.
That said, terminating a coax with DC voltage on it is also ill advised if the terminator has a 75 ohm resistor to ground.