That's basically correct. There is the Vatican document on Catholics in political life which outlines the moral principles which must guide Catholics on issues of human life. Technically,as I understand it, the issue regarding Communion is one of "discipline" and at the discretion of bishops to determine. What seems to be going on is "collegiality" - individual bishops consulting with one another on how they understand the issue. It's clear that someone who is involved in propaganda and political campaigns to promote abortion is no longer a Catholic in good standing. And he or she should not be receiving Holy Communion while engaged in the public scandal of promoting grave evil - the murder of the unborn. Now, finally, some bishops appear ready to enforce this. Or, at least, make it known that that is the policy in effect in their diocese. We shall have to wait and see whether priests and bishops actually take the next step and deny such pro-abortion Catholics (that sounds horrible doesn't it?)Communion at actual Masses.
One positive effect of this will be that it will make clear which bishops are truly and courageously Catholic. That will be good for the Church and good for the world.