problem is it’s a supersonic fighter with 4 IR and 4 SARH, giving IRCCM will inevitably bump the EJ Kai BR up. For comparison in 12.3 you had the slow GR.7 Harrier being the all 4 IRCCM slinger (with BOL) and MiG-21 Bison while also supersonic and can carry 4 R-73 still limited on choice for either 2 SARH and 2 IRCCM or all 4 IRCCM (and they even got HMD with). Heck even MiG-29 was refused to give back R-73 to sit at 12.7 just because it can carry 6 with HMD included and they had to make 2 models to separate 12.7 and 13.0 (even though people have suggested it to get R-73 by removing the R-27ER/ET missiles).
to F-15J which already have 4x AAM-3 and 4x AIM-7M, 12.* literally most broken BRs. Moving EJ Kai have no sense at all, also R-73 with HMD much more deadly than AAM-3 without
F-4EJ Kai now half dead, it’s still pretty playable plane, but 40% of your enemies would be FOX-3 users (because nearly half of the games are uptiers), and what counter part you have? AIM-9L and AIM-7. Moving it to 12.7 will kill it, no matter will it have AAM-3 or not, even with “XAAM-4” it will die
it won’t change the fact that they will not give it anyways without bumping the BR up because it’s a supersonic fighter that has 8 AAMs even though it’s a brick, again other than the Bison and GR.7 mentioned earlier, other IRCCM carrier below 12.3 only carries 2 like the Mirage F1C and 2000C-S4/S5, the Su-25T/39/25SM3, JH-7 at 11.7(which is diabolical for the performance it has), A-10C won’t count because of their obvious being slow(and yes I know it carries 4).
We can say F-4EJ Kai to get AAM-3 and let it stay at 12.3 but no way they will let it happen or not before bumping the BR for balancing measures. Just think it’ll be a menace at 11.3 or 11.7 with like theoretical 4 or 6 kills (I fly Mirage 2000 on 11.3 downtier twice and it already so menacing to get 4 kills with 2 Magic II being easy confirm kills plus Super 530D, let alone F-4EJ Kai with 4 AAM-3 and 4 AIM-7M) even though downtier chances are nowadays slim thanks to Su-30MKK, F/A-18C Early, Su-33, F-2A ADTW and now F-14D.