The author of the linked article points out there are competing interpretations under which mass-energy is still conserved on the small scale. It's just that i

The author of the linked article points out there are competing interpretations under which mass-energy is still conserved on the small scale. It's just that if you introduce the variable of local gravitational energy you wind up with a system of more variables than equations. We don't presently know of any laws that further constrain the system of equations to a unique solution unless we take local conservation of energy as an axiom... which of course prevents us from proving local conservation of energy. However, we don't have any observations that are inconsistent with local conservation of energy if gravitational energy is taken into account.