From a photons perspective, emition and absorption are simultaneous.

While from our perspective it is a form of causal connection, that is mearly due to the frame of reference.

While we can infer the connection between each, it is possibly better to consider the speed of light as the speed of causality.

But as there are no privileged reference frames under GR the choice is yours.

But from the photons perspective, it doesn't experience time at all so it can't be a barrier.

But don't confuse the map for the territory. GR is a model, not the system itself.

The fact that almost every test we can figure out has only confirmed it doesn't change that.

Under the 'all models are wrong but some are useful' idea, in GR photons not experiencing time is important to that model.