Below are several area of planning a Spacecraft Trajectory that will benefit if maneuver nodes do take into account atmospheric friction!
Landing Prediction on an atmospheric planet
More complex aerobraking maneuver
Etc (Reply down bellow if you have more ideas!)
I will be mostly talking about aerobraking because this feature would help a lot on planning aerobraking maneuver, such as better fuel economy because if you can see where your spacecraft might be going after an aerobrake, it would be very helpful if lets say you want to intercept Laythe after slowing down massively in Jool's atmosphere, i find this to be very tricky in KSP 1, I had several mods to help me but even still its a bit finicky.
I understand that this feature might be difficult to incorporate into the game considering the prediction wont be 100% accurate and can be affected by many factor during the aerobraking, here are examples of several factor I could think off that might throw off the prediction
Angle of attack during the aerobraking maneuver
Parts getting blown off causing a slight change in the vessel's aerodynamic characteristic
Etc (Reply down bellow if you can think off more affecting factors!)
I have no idea how difficult a game development is, so I don't know if these feature are even possible to incorporate nicely into the game
but if this feature is going to be added into the game even if its much later, it will still be a very nice addition into the game
P.S. It would be awesome to recreate some shots of the Leonov aerobraking maneuver from 2010: The Year We Make Contact in KSP2 with some beautiful atmospheric friction effects