Monty Hall's paradox: is there any difference?

This paradox is familiar to many, and even, as I recall, was even mentioned on the pages of Habr .
However, I propose not to discuss once again the actual problem, but the specific part of the paradox, which states that

Initially, the probability that the participant gets on the car is equal to 1/3. After the presenter opens the door, most people think that it should be 1/2, but this is not the case. The presenter knows where the car is, and therefore does not open the door with the car. And the probability would be 1/2 only when the leader would not know the position of the prizes, and then opening the door would not change anything.

And the key point is precisely the knowledge of the leading "right" door .
')
And here in this place I personally and begins to fail. In my humble opinion, the fact that the presenter’s knowledge and his deliberate choice of the door with the goat allows us to know in advance that we will change our choice after the offer. However, if the events have already come, then we have no difference what the guide was guided by, opening this or that door. We are only important fact, which has already happened.

So I would like to discuss with the public - are the authors of an article in Wikipedia too much emphasis on making a conscious choice of a facilitator, or am I misunderstanding something?