Well, maybe not now, but in 2019/2020 (when the next normal release / LTS release is due). We need to continue with the regular release schedule past that point for the reasons I outlined in my previous post.
I fully agree with @ooeygui’s suggestion to make the API transition gradual in order not to split the developer base. Not out of charity for ROS1, but to give ROS2 a shot at survival; I don’t think it’s a foregone conclusion that ROS2 would win if the developer base is split at this point.
I’ve used ROS since 2010, and I’ve seen many examples of new APIs being introduced (rosbuild to catkin, tf to tf2, C++98 to C++11, …), and it always took many years until the majority of packages was updated. For example, tf2 was available since at least 2013, and navigation switched to tf2 only last month. Since ROS1 to ROS2 is a much larger step than any of those examples, I’m afraid it will take much longer than that for the majority of packages to migrate to ROS2.