What they gonna have end credit scenes of Thor hyping up AIM?
All they've literally done with Thanos is create hype by introducing the infinity stones.
What they did with Hydra was surprise us that they sort of won after the war and embedded themselves in SHIELD and all around the world and then they were ready to strike. That's a one time twist that puts them at the top of the list when it comes to terror groups.
For AIM to get that treatment every Iron Man movie would have to involve them and they'd probably have to have some influence in one of the Cap movies. There'd have to be thought out plan. Same goes for the 10 Rings if they were a separate thing and there's no way both groups could get that sort of execution when the only 3 franchises at the time were Cap, IM, and Thor. What they ended up doing for AIM though is saying they secretly were the 10 Rings. They made up a fake terrorist group and a puppet Mandarin for sort of monetary or political gain. That was the whole point of dude revealing that to Stark. That was the most put in to AIM story wise while weaving in the continuity of mentioning the 10 Rings back in IM1. That's another thing, in the comics there is no such group called the 10 Rings. I think it's something Faverau or the writers made up to reference the Mandarin's 10 magical alien rings that give him power back when they weren't sure the Mandarin with that power set would ever show up. So they said lets make it a terrorist faction which played on the zeitgeist of our time.
Thing is Iron Man was a risk flick, so were Thor and Cap. Marvel didn't know it would work so it made no sense to have a big plan setting up multiple villains the same way they set up just for Thanos. When they got traction that's when they started laying the foundation and Avengers revealed after the fact that certain objects that don't even look like infinity stones are infinity stones.
Plus if they did so much planning for each villain like that there probably wouldn't be the bigger Thanos and Infinity gauntlet climax. I mean that's plans within plans. A lot of moving parts. Not to mention the different directors on several of these films. So there alone you know execution will not be consistent. Phase 1 the MCU is still finding their groove even when it ended with the success of the Avengers. The idea was probably just good entertaining movie with a framework for future sequels but if something doesn't work out we'll switch directors and adapt or scrap the franchise and keep moving.
I'm not saying it's a bad idea going forward though but that'll come after IW.