He dropped out of Strictly cause, a number of dates from his show with Curtis had to be cancelled due to Covid lockdown and he clearly thought he was far more popular then he is & rather then reschedule the tour for the following year like all the other pros did, he rescheduled for September. Obviously the rescheduled dates didn't happen and Strictly weren't going to take him back at that stage.
So him and Curtis have announced a new tour for next year, doubt it will sell well though, as AJ's tour wasn't selling well and so he got Curtis to be in it, as he still held a good bit of popularity from Love Island and had the popularity from going out with Maura, who he only broke up with about 2 weeks before the tour actually started. As far as I know even then they didn't sell out any venue. AJ would have only been signed for I'm a Celeb in late September/early October, so him appearing on IAC has nothing got to do with him leaving Strictly. He left Strictly cause of his huge ego and thinking he was bigger then the show.
AJ has also done numerous magazine interviews since leaving Strictly saying how he had to turn down opportunities because the BBC had to approve any work the dancers do outside of the show most likely it's tv appearances on shows like celeb juice or the Love Island panel, stuff like that which isn't family friendly & the bbc has always tried to portray Strictly as family friendly, so wouldn't want the dancers appearing on shows like that. AJ also said that Strictly was all about the celeb and he never got to show who he was as the focus of the show isn't on the dancers. The final nail in him ever appearing on Strictly or any other bbc show again was in an instagram post where he said ilIAC is a better then Strictly.