The CRFI [doc] puts down that the primary mission in the future Next Gen TACAIR definition is Offensive and Defensive Counterair to include subset missions including Integrated Air and Missile Defense (IAMD), Close Air Support (CAS) and Air Interdiction (AI). It may also fulfill airborne electronic attack and intelligence-surveillance-reconnaissance capabilities… The future system will have to counter adversaries equipped with next generation advanced electronic attack, sophisticated integrated air defense systems, passive detection, integrated self-protection, directed energy weapons, and cyber attack capabilities. It must be able to operate in the anti-access/area-denial environment that will exist in the 2030-2050 timeframe.
Some of the technologies the US gov wants to know more about include non-kinetic weapons, secondary power generation, heat rejection and optionally manned systems.
Suddenly the whole fourth generation vs fifth generation argument seems to … well, dwindle.