I’m not sure if you are referring to something specific in that post but no, quite the opposite - LIGO confirmed Gravitational waves, predicted by Einstein’s general relativity.

The Michelson-Morley experiments were a failure in that they didn’t find what they were looking for (Aether), but relativity came out of trying to understand that “failure” (rather, the null results of the experiment - calling not seeing something you expect a failure is an oversimplification)

Maxwell's equations show that the speed of light is invariant in all inertial reference frames. In other words, the speed of light is the same no matter what speed you are going. This was a bigger inspiration to Einstein than the MM experiments.