Could it bee possible that in original timline where Barts from the Reach killed Jamie on the Reach ship due to the fact that Impulse( Bart ) would of never of been there to save him when the Reach scientist ladie was trying to kill him in order to remove the sacarb so she could reboot it etc. Just note that in the original timeline Tigress and aqualad would of still been undercover and Aqulad would of still given Nightwing the flash drive with the info on the Reach's activities. Note : Impusle arrived on February 28th 2016( Bloodlines ) which at this time only Aqualad would of been undercover not Artemis due to the fact the the events of 'Depths' not occuring yet.
( Original tmeline aka Impulse's Future )..So say that the scientist female suceeded in killing jamie in that containment pod , she would of killed him and removed the scarab from his back. They would then needed to find a new host.....so it might be still possible that the Blue Beetle of the future is someone else , but due to Bart's interference in the timestream it may turn out slightly different out different. For instance.....The Reach failed to kill jamie in that pod because Impusle saved him which prevented them from killing him and removing the scarab thus The Reach had to find another way to get the Blue Beetle under conrtol and their side. Also another change impulse affected was the Neatron incident.
Is the Blue Beetle in Barts's future really Jamie Reyes????