Mari et al. [Sci. Rep. 6, 22777 (2016)] and Belenchia et al. [Phys. Rev. D
98, 126009 (2018)] explore a gedankenexperiment in which the (gravitational or
electromagnetic) interaction between two objects, one placed in a state of
quantum superposition of two locations, seems to allow for faster-than-light
communication. Building on the analysis carried out in Mari et al. [Sci. Rep.
6, 22777 (2016).], Belenchia et al. [Phys. Rev. D 98, 126009 (2018)] argue
that, by considering the quantization of radiation and the existence of vacuum
quantum fluctuations of the fields, the apparent possibility of superluminal
signaling is completely avoided. Moreover, in the gravitational case, such a
conclusion is taken as providing support for the view that gravity must
necessarily have a quantum nature. In this work, we reconsider the situation
and find several limitations of these assessments.Comment: 13 pages, 1 figur
