So with Center-Left Opposition and JCP forming alliances in all the battleground 1- member districts the medium case for the 2019 July Upper House election would be for the Constitutional Revision bloc to lose its 2/3 majority and with it Abe's goals of Constitutional revision. I think now we can get a real sense of what Abe's true priorities are. If he does value Constitutional revision above else he should actually go ahead and call a Lower House election and have a double election as a referendum on Constitutional revision. If there is a pro-LDP wave from this issue this should be enough for the pro-Constitutional revision forces to win 2/3 in both houses. If not then Abe's would lose seats in the Lower House and his leadership stature diminished. The window is closing fast for Abe to do this.
I think Abe wants the Issue more than Constitutional revision itself. A revision would be solely symbolic in nature anyway.