At this point with where we are in DC Post Rebirth is Crisis on Infinite Earth's still necessary for continuity? Barry has been back for years as well as the Multiverse in general. Convergence tried to undo it but in the Button I do believe we saw that it is still indeed part of the current timeline. Infinite Crisis tied heavily into Crisis on Infinite Earth's but without Superboy Prime around how do we know he is even still a part of DC's overall history?