A Cat B rookie is outside the list of 44. I do know they can be upgraded for a LTI, but I am unsure if they can be promoted outside of that reason unless there is room on the main list and we have not exceeded a total count of 44.Hence why we didn't use pick 90.
Passing on a rookie today is completely irrelevant to that though. If there's a free spot on the main list, it doesn't matter if we have one or ten rookies on the RL, we can upgrade one.