#2 Future partnerships with these wrestling promotions
Cody Rhodes and The Young Bucks promoted All In by working on countless independent wrestling shows. They did the same to promote Double or Nothing and it proved to be a great strategy.
One could now argue that AEW doesn't need to promote their brand anymore because they are already making headlines and TNT will help to promote their content, which is true. But as of now, despite the TNT deal, WWE remains to be the biggest wrestling promotion. They haven't had any serious competition since WCW died and it would be wrong to say that AEW is a 'legit' competition to WWE, at least now.
Vince McMahon has made WWE a billion-dollar company and to topple it, AEW would need support from wherever possible. We have already seen many ROH and NJPW crossover events and since AEW wrestlers are already working for the Japanese promotion, could we see a partnership between the two? It may not happen now but it could happen at some time in the future as per Dave Meltzer.