Carlo Rovelli: "If we have learned that the earth is not flat, there will be no theory in the future in which the earth is 'flat.' If we have learned that the earth is not at the center of the universe, that's forever. We're not going to go back on this. If you have learned that simultaneity is relative, with Einstein, we're not going back to absolute simultaneity, like many people think."
The relativity of simultaneity, together with other absurdities (length contraction, time dilation), belongs to the "protective belt" of Einstein's 1905 false light postulate:
"Lakatos distinguished between two parts of a scientific theory: its "hard core" which contains its basic assumptions (or axioms, when set out formally and explicitly), and its "protective belt", a surrounding defensive set of "ad hoc" (produced for the occasion) hypotheses. (...) In Lakatos' model, we have to explicitly take into account the "ad hoc hypotheses" which serve as the protective belt. The protective belt serves to deflect "refuting" propositions from the core assumptions..."
The protective belt ("contracting lengths, local time, or Lorentz transformations") referred to by Banesh Hoffmann:
"Relativity and Its Roots" By Banesh Hoffmann: "Moreover, if light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd: A stone thrown from a speeding train can do far more damage than one thrown from a train at rest; the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations. Yet, as we have seen, Einstein resisted the temptation to account for the null result in terms of particles of light and simple, familiar Newtonian ideas, and introduced as his second postulate something that was more or less obvious when thought of in terms of waves in an ether."