Nonsense. This administration erased entire programs with the stroke of a pen. A future administration could do the same. Everything this administration has done can be unraveled.
look at the longevity of the Patriot Act - once in place ("because of X!") it's extremely difficult to kill as all kinds of forces work against killing it and it's easy to scare the public about "what will happen if it's not there"
They will have the power to at very least lay off every person involved. But will they? Probably not (your point). Trump (illegally) shut down the DOE and USAID by simply firing everyone employed there.
Pretty much the exact opposite.