I can see that, sure.
It feeling like a workaround for Defiling and Preserving does make sense... but Defiling was meant to be the easy path to power in the setting. You got a shorter XP table if you were a defiler as a reward for embracing evil and would level up as a Wizard faster than if you were a Preserver.
So while it was certainly a way -to- sidestep... that wasn't the goal. Also everyone getting Wild Talents was a big deal. Previously you rolled for those.
It wasn't included in the 2024 PHB. However it also hasn't been addressed. And "This is the law of the Multiverse and how magic functions everywhere across all time and space" feels like it needs a specific response, to me.
YMMV, of course. But so long as it's "Still 5th Edition D&D" then it still has 5e's baggage 'til they drop it, IMO.
"A Note About Psionics"
"Dark Sun is a world of powerful psionics. Every player character has at least one psionic talent, as do many of the non-player characters and monsters. A thorough understanding of The Complete Psionics Handbook is required for full enjoyment of any DARK SUN campaign"
So let's check the Psionics Handbook.
"Is Psionics Magical?"
Many people assume that psionics is just another type of magic. The AD&D* game already has two types of magic - one wielded by wizards and the other by clerics. So it is not unreasonable to ask, "Does the game need a third type of magic?"
The answer is no, the game probably does not need a third kind of magic.
But the question is misinformed because psionics is not magic. Magic is the ability to shape, control, harness, and utilize natural forces that infuse the game world and surround the characters. It is based on the principle that, through the use of words, gestures, and catalyzing materials of unique power, these external energies can be controlled.
The key element of that statement is external energy. Magical effects are produced externally by manipulating outside forces. The power does not come from inside the wizard or priest but from somewhere else.
Psionics is the complete opposite of this. The psionicist shapes, controls, harnesses, and utilizes natural forces that infuse his own being. His effort is focused inward rather than outward. He must be completely in touch with and aware of even the tiniest workings of his body and mind.
This type of knowledge comes from long and intense meditation coupled with physical extremes. The psionicist finds enlightenment in both complete exhaustion and complete relaxation, in both pain and pleasure. The mind and body are only parts of a much greater unity. Indeed, discussing one without the other, as so many people do, seems nonsensical to a psionicist; they cannot be separated. The body produces energy and vitality, the mind gives it shape and reality.
Neither does the psionicist study or pray for his powers. He carries them with him wherever he goes. As long as his mind and body are rested - i.e., as long as he has not depleted his psionic strength - his powers are available to him."
So no. Psionics in original Dark Sun are not magic.