Hand-in-hand adding new AI aircraft with versions appropriate for a wider audience of nations. As ED seems to be really expanding Naval Ops let's keep that rolling with maritime aircraft, but by no means let it limit what you can add.
Examples:
Lockheed P-3 Orion/CP-140 Aurora serving: USN, RNZAF, JSDF, RAAF, ROKN, RCAF
Br.1150 Atlantic serving: French Navy, German Navy, Italian AF, Pakistan Navy, Royal Netherlands Navy
Airbus A310 MRTT/CC-150 Polaris serving German Air Force, RCAF
S-2 Tracker serving: USN, Royal Canadian Navy, Argentine Navy, Brazilian Navy
C-1Trader/C-2 Greyhound serving: USN
Hawker Nimrod MR1/MR2 serving: RAF
Ilyushin Il-38 serving: Russia/USSR, India
SA 330/IAR 330 Puma serving: French Army, RAF, Romanian AF/Navy, Pakistan Army, Lebanese AF, UAE AF, Sudan AF
Additionally some existing AI should be updated and re-skinned.
Examples:
Lockheed C-130 serving: RAAF, Royal Bahraini AF, Bangladesh AF, RCAF, RDAF, Egyptian AF, French AF, German AF, Indian AF, Israeli AF, Italian AF, Kuwait AF...
With all the new modules, AI naval vessels, and hopefully new physics for submersibles this would really make mission creation and immersion grow.