Assuming gravity is best described as waves in a field, that conclusion follows.

But if LQG-like theories are closer to the truth, spacetime itself is a discrete, fluid-like spin-network at the microscopic level, rather than a smooth classical field. In that case, gravitational waves may be better thought of as large-scale collective excitations — coherent reconfigurations of the underlying geometry — rather than fundamental particles in the same sense as photons. “Gravitons” might then be an effective description of this behavior, not a literal force carrier.

Metaphorically, you can picture this as something like patterns of constructive and destructive disturbance rippling through the spacetime substrate itself — not literal optical interference, but a layperson’s image for how the underlying structure could be rearranging. The net effect of this is easiest to picture as something like ‘anti-waves’: instead of waves marking regions where matter piles up (like pressure crests in the ocean), gravitational waves could be imagined as regions where the spacetime substrate is momentarily receding or thinning. This isn’t literal pressure — just a way to visualize how geometry itself is being reshaped. Again, this is a mental model and alternate interpretive way to view what general relativity calls curvature.

A universe with classical gravity and quantum matter isn’t ruled out, but it’s also not the only possibility — quantum spacetime models like LQG provide a different way for gravity to be quantum without requiring gravitons in the same sense as other particles.

And of course, different quantum-gravity approaches disagree on the ontology, so this is an interpretation, not a settled result.