First of all, the headline says one thing, but the quote you gave from Mr. Poilievre is slightly different.
Mr. Poilievre—don't quote me, I'm just going on the basis of what you just said—is talking about appointing people who are ready to implement the government's agenda. When there's a transition in government, especially after a long period of time, it's not surprising that an incoming government has a certain tack it wants to take—an agenda, a program, a Speech from the Throne—and that it expects some of the commissions to move forward in line with that agenda. It's the government of the day, the democratically elected government, and it expects the whole of the government apparatus to move in the direction of the government's program.
So saying that they want to appoint people who will advance their agenda is a legitimate comment from a new government in the midst of a transition.