The ability to just roll things back that are law is not as simply as policy. To do this, the GOP would have to have all three branches.
As for the ability of the agencies to change things, that was just undone by the Supreme Court. The wings of agencies was clipped severely.
So the idea that Trump is going to roll into the White House, if he does, and just undo the laws that are in place is campaign wishes.
That's not to mention that traditional buyers of Tesla vehicles are unlikely to support this move towards Trump, while conservative supporters are far less interested in purchasing EVs... especially once there are credits available for ICE vehicles.
Even if that were true, which is no longer the case, what are those on the left going to do, buy ICE vehicles? What EVs are they going to buy? GM? Mary Barra had to admit they are not going to reach their target of 1M EVs in 2025.