Basically, there is crowd sourcing already for FSX. It's called the AVSIM Library. I'm sure Dos Equis will have a spot there as well. Word of mouth vets it pretty well as far as value to the end user.
You could start your own 'official' addon repository if you want greater control.
Flight Sim World had a scheme for 3rd parties to be vetted by stating any 3rd party content could be used (stolen) as official Dovetail property... didn't work out so well for them, as they lost all 3rd party support almost instantly. Flight also doomed itself they same way.
Asobo is doing a decent job of creating basic scenery as part of the sim. But I don't believe they (or Microsoft) will want to revisit every airport to approve 3rd party addons. I think it will be better than what the basic X-Plane offers. They already have an Alpha ongoing to address things like content inaccuracy, and I believe they will have an "in game" app that will allow redesign of things like runways and taxiways and the like. With aerial imagery as a base of the sim, I would think they'll strive to get the airfields done right from the initial release. Discrepancies in core elements will be patched over time, and 3rd parties are going to be able to request airfield corrections to the core. They state they have a long-term commitment.
I do understand some end-users are collectors. They collect world-wide imagery and mesh and landclass. Other collectors gather airfields. Some collectors gather aircraft. These simmers drive the commercial 3rd party industry. The collectors rarely will visit 1% of the world the sim covers, nor fly 1% of the available 3rd party aircraft with any regularity. Demanding, or even desiring, 100% detailed accuracy of everything as a core element of the sim is not realistic. There would then be no need for 3rd party developers, and there would be no fun for the collectors. The sim would be complete. And a great many developers and collectors would move on to another sim or game to continue doing what they like to do. The only ones left would be the simmers that just enjoy the process of flying.
The formula for a successful flight simulator is FSX and by proxy P3D. It has made a lot of money for Microsoft, Dovetail, Lockheed-Martin, many 3rd party developers, and provided a strong group of end-users, and countless freeware 3rd party addons as well. FSX is a sandbox. It is versatile. Improvement of the sim drives interest. To change the formula to have approved and official 3rd party content added as a core component is not part of that successful formula. It would hamper content development and experimentation, and essentially kill the sim.