Your guess doesn't really make any sense and doesn't fit the timeline.
Topuria won the FW belt about 15 months ago, Belal won the WW belt last July, Topuria fought Max in October and didn't vacate the FW belt until February, and Hunter Campbell went to Dagestan like 6 weeks ago right fore JDM/Belal.
There are a lot of moving parts, but Islam had just defended against Poirier and was most likely waiting for Leon Scott to beat Belal so he could fight Leon later in the year since he was nearly a -300 favorite, but Belal won and Islam/Belal wouldn't fight each other, so he stayed at LW to fight Arman who wanted 6 months to prepare for Islam.
Islam signed to fight Arman for January(though Arman pulled out the day before), right after Evloev beat Aljo and Shavkat beat Garry, so Shavkat was the plan to take out Belal, and they probably didn't want to risk Evloev beating Topuria, so they offered Ilia a title shot at LW if he vacates.
The plan shifting was probably the 6 months between Belal winning and when Islam was supposed to fight Arman. Arman was out of the picture after his stunt, so Islam took a replacement and was probably waiting for Shavkat/Belal, so they promised Ilia a title shot but they had to wait on Shavkat/Belal to find out against whom. Shavkat got injured, JDM stepped in as an underdog, Islam was waiting to see if Belal would still be the WW champ which was the odds favorite to happen, and Hunter Campbell went to Dagestan to talk Islam into fighting the winner no matter who won, Islam probably said only if JDM won, and they probably landed on him fighting JDM if he won, or a date to fight Topuria if Belal won.
There's not really any other reason they would have waited so long for Topuria to vacate the FW belt and not give him any contender fight for like 9 months if they weren't waiting to see where the WW title was for Islam to move up. Topuria's pretty marketable, so fighting Islam was a last resort if everything else fell apart, since Islam would have most likely ragdolled him and choked him out which would do nothing for Islam and would leave Topuria without any title. Charles isn't a great wrestler and is older, so that is much more favorable for Topuria, and Islam now has a more interesting fight with JDM then probably make Brady/Shavkat for Islam to fight the winner.