Yes, it is true that the differences between Chess960 (Fischer Random Chess) and traditional chess go far beyond just opening theory. The starting position of the pieces in Chess960 is completely random, which means that players cannot rely on established opening theory and must use their strategic and tactical skills to create a winning position from scratch. This creates a level playing field for players of different skill levels, as the advantage of having memorized more opening theory is largely eliminated.
In addition to the lack of opening theory, there are other strategic and tactical differences between Chess960 and traditional chess. For example, the placement of the pieces in Chess960 can create unusual pawn structures and tactical patterns that are not commonly found in traditional chess. This requires players to think creatively and adapt their strategies and tactics to the unique position at hand.
While it is true that all the pieces move the same in Chess960, the lack of a fixed starting position creates a significant difference in the strategic and tactical requirements of the game. Therefore, the skills required to play Chess960 effectively are different from those required to play traditional chess, and players may excel in one format more than the other.