#3 Their television deal is yet to come into effect
So far, AEW has only held Double or Nothing and they have already become the biggest competition to WWE. They have also partnered with WarnerMedia Entertainment who will broadcast AEW events on TNT later this year. No specific dates have been revealed yet but we can expect their television deal to begin after All Out pay-per-view, which will happen on August 31.
As long as AEW isn't airing on TNT, they wouldn't have any problems with their wrestlers working outside the company. After all, they are committed to hosting just one show per month. It means that their Superstars will have a ton of free time to work.
It's a possible reason why Tony Khan may have allowed his wrestlers to work wherever they want. And when AEW will begin airing on TNT, he could restrict his wrestlers to work with other promotions or just allow them to work on only a few dates.