Every Tesla is different (sadly), hence will have a slightly different amount of noise depending on how well the glass seals against the rubber around the door.
There is a lot of adjustment in the glass in 6 directions (up, down, left, right and inward and outward), so a lot of room for error.
The suggestion seems to be that the double paned glass does not necessarily decrease noise in and of itself. You could find, however, that fitting it (and improving the seal in the process) makes you think it’s made a noticeable difference, when it hasn’t- strictly speaking.
In terms of retrofitting - it is a straight swap. The internal door hardware was unchanged.