User blog comment:Eobard95/Is Flash trying to preserve Laurel?/@comment-28501280-20180426004035

I think you’re over thinking this. They needed an Earth X villain to tie in with Snart and Katie was absent during the crossover and already has a villain costume so it was an easy fit. I have little reason to believe that there’s any deeper reasoning behind it other than it was a simple answer to give fans a cool character.