Title is self explanatory. The current Aim-9M is severely lackluster with a poor, highly flareable seekerhead, horrendous range, and actually less initial pull than the R-73 (refer to vid where R-73 hit the target at angle impossible for any other missile in the game).
Aim-9X is already currently modeled and being tweaked in almost every patch. The seeker is much better, and the range would not be that of the R-73 but atleast give US and potentially EU some sort of Dogfight capability besides the AIM-7M/F which at most you are guaranteed a trade.
Aim-9M is already better than R-73 in most common situations except pure close range dogfighting, especially because of it’s İRCCM, this is pure copium.
Adding the 9X would leave some nations in game without viable comperable missiles without artificially nerfing most of them.
Currently Magic 2 is seemingly seeker gimped because the R-73 and its limited capability seeker.
Magic 2 being 4 element seeker and R-73 2 elements. Currently in game they are the same once launched. (Edit: at least the current situation is fine given that its just the french who would complain)
There is no IIR seeker missile for the Soviet tree in the current roster of nations in that tree.