I don't agree (I'm the author).

The difference is that Monty knows which of the doors the car is behind and deliberately avoids it, thereby giving away information about where the car is.

Whereas in Minesweeper we've just blindly stumbled across a situation where we have to guess.

It would be like if every show Monty always revealed a random door. Sometimes he would reveal the car and the game would end immediately. In the cases when he didn't reveal the car it really would be 50/50 between the remaining two doors.

I agree, its definitely not Monty Hall, and IDK why they are so confident.