Well, there is a difference between Kyle and John, Jessica, and Simon, in that the former carried a solo title for over 100 issues, and thus, putting him in a title that resembles his most successful run could be perceived as endangering DC plans for Hal. It could be a factor, especially with GL nowadays selling around 40.000 issues per month. Imagine if, somehow, a Kyle-led title sells approximately 30.000. What would that say about the current GL title?