@The Durable Don > He does add information. Reduction of uncertainty is always about added information. See Shannon's Entropy. By removing one door he reduces the odds from 1/3 to 1/2 for both leftover positions. Exactly the same for the 100 doors. Which started at 1/100 and ended at 1/2. So here far more information needs to be added to reach the same level of uncertainty. But the value of both final positions is exactly the same: 1/2.

Thinking that this is not so is the precise reason people at casinos keep betting on black, thinking wrongly that the more times it's fallen on red increases the chances of it now becoming black. (ergo the more doors removed "increases the chances" of the non-chosen door relative to the chosen one. it doesn't. Both door chances increase equally.

PS The fact that the table shows that you have 1/3 chance to win on any given door position (3 on door 1, 3 on door 2 and 3 on door 3) should have rung some bells instead of being misguided by the presented 3 versus 6 change = win positions. Because changing door forces you with 2 options (door 3 if door 2 was opened, and door 3 if door 2 was opened) reducing your magical 2/3 "win" back to statistical reality.