Given his age, there is a non-zero chance that he may die while in the presidency?
JD Vance isn’t exactly a charismatic individual (some might even go so far as call him ‘weird’); so this entire neo-fascist movement may very well fragment and flounder in the not too distant future.
If he dies before they are able to really get the structural changes in P2025 off the ground, Trump's death will likely instigate the death of the movement. If it dies after that the P2025 restructuring has happened, won't matter.