  Whether gravity is quantized remains an open question. To shed light on this
problem, various Gedankenexperiments have been proposed. One popular example is
an interference experiment with a massive system that interacts gravitationally
with another distant system, where an apparent paradox arises: even for
space-like separation the outcome of the interference experiment depends on
actions on the distant system, leading to a violation of either complementarity
or no-signalling. A recent resolution shows that the paradox is avoided when
quantizing gravitational radiation and including quantum fluctuations of the
gravitational field. Here we show that the paradox in question can also be
resolved without considering gravitational radiation, relying only on the
Planck length as a limit on spatial resolution. Therefore, in contrast to
conclusions previously drawn, we find that the necessity for a quantum field
theory of gravity does not follow from so far considered Gedankenexperiments of
this type. In addition, we point out that in the common realization of the
setup the effects are governed by the mass octopole rather than the quadrupole.
Our results highlight that no Gedankenexperiment to date compels a quantum
field theory of gravity, in contrast to the electromagnetic case.
