The more likely headcanon is that, after the death of his original body, Palpatine spent a considerable amount of time in a sort of “limbo”, as a powerless spirit barely clinging to the material world until he managed to eventually inhabit the clone body on Exegol. Sort of how Sauron’s fate is described after he first loses the One Ring in the backstory of LOTR: his body being actually slain only for his spirit to endure and (very) slowly recover his strengths until he could take a physical form again.
That way he does indeed die, fulfilling the prophecy and all the technicalities, yet despite his eventual return he’s incapable to intervene or take command of the Imperial remnant.