Quite true. I think good stealth coating have a point against small and weak X-band ARH homing heads in AA missiles like R-77, AMRAAM, MICA, Meteor, etc. They have to come very close to lock on stealth plane (less than 1 km), so they have no more value than old SARH missiles, because you still have to guide the missile to the plane. Now, fact is, that only MiG-31 and Su-35 have L-band "radar" elements. MiG-31 have those L-band elements build inside Zaslon radar antenna, Su-35 have them as additional L-band AESA elements in the wings. Saying this is only IFF, I will not buy it. This is a waste of money and energy to use those expensive elements only for IFF. We know, that MiG-31 use those L-band elements with R-40 missiles, maybe even with R-33. R-37 and RVV-BD missiles are based on R-33 missile and it have quite big ARH homing head, so maybe it use L-band antenna inside, to be used in L-band in SARH mode or maybe even in ARH. Anyway, stealth F-22 or F-35 are not that stealth in L-band as in X-band, so those missiles could easier lock on them and in longer distance than classical ARH missiles. Also planes are usually equipped with jammers in X/S-band and not that often in L-band.