I have always been using the LJ sights to determine the angle at which to shoot, that's why I noticed the change pretty quickly. The "1" notch and the "2" notch never really lined up with "1000m" and "2000m" distance to target (that is, put target in between these notches if it is that far away) as I first assumed, but were helpfull nevertheless after some experience with the gun.
If you use the map to determine distances, the max range and arming range markings wouldn't be as helpful as if the notches for 1 and 2 actually lined up with 1000m and 2000m but would still be as helpful as the sights were before, just with the additional info of arming range. Besides, do LJ shots even have a lifetime? I think there's no need to add a "max range" mark to it when you simply reach max range by pointing the gun 45° into the air.
For the Hades: There are a few notches on that gun, 6 I believe, but when the target is on the same height as the gun, the smooth arc makes using any notches besides the uppermost two useless. Removing the visorshield would help aiming that gun a lot more since it sucks to have to lead targets left thanks to that.