Can you do it? Yes. Should you do it? Absolutely not.
Magic is unusual in Dark Sun. Divine magic mostly only exists through the will of the Sorcerer Kings, with the rare halfling druid as the exception. Arcane magic is what destroyed the world, and its use is generally despised by most. This leaves Psionics as the third alternative to "magic." By removing it, you force the players to either work for the Sorcerer Kings or hide their abilities completely. Since working against the Sorcerer Kings is part of the common theme of Dark Sun, by removing Psionics you remove a fundamental aspect of the setting. I don't even like Dark Sun and I know this.
Magic is unusual in Dark Sun. Divine magic mostly only exists through the will of the Sorcerer Kings, with the rare halfling druid as the exception. Arcane magic is what destroyed the world, and its use is generally despised by most. This leaves Psionics as the third alternative to "magic." By removing it, you force the players to either work for the Sorcerer Kings or hide their abilities completely. Since working against the Sorcerer Kings is part of the common theme of Dark Sun, by removing Psionics you remove a fundamental aspect of the setting. I don't even like Dark Sun and I know this.