Economies change slowly. To eliminate the demand for Russian Natural gas on that time scale means that they are going to have to import it from somewhere else.

Economically speaking the only move that justifies that price premium is if one wanted to unload their Dollar position and the time frame needed to do so would align with their fossil fuel reduction timetables.

It is not about them moving to a new reserve currency but unwinding the current position in a way that aligns economically and politically for their own countries.