  Christodoulou and Rovelli (CR) [1] have argued that a Bose et
al.-Marletto-Vedral (BMV) experiment that confirmed the quantum nature of
gravity would give laboratory evidence for a quantum superposition of spacetime
geometries created in the course of the experiment. Hanif et al. [2] have
argued that mass interferometers can be used to test whether gravity acts as a
quantum entity when measured. We note that not all quantum models of gravity
imply that mass superpositions necessarily become significantly entangled with
any degrees of freedom of the gravitational field during the experiments
discussed.
