I do dislike the fact that the "rules" are being toyed with.
The only rule involved is Exodus 20:13. That has not been changed. The only difference is an administrative adjustment to accommodate the expected surge of penitents, nothing more.
How come a woman who had an abortion in say, Argentina, but never went to the World day, would not get the same treatment?
She could get the same treatment at home: confession at any Catholic church she chooses for forgiveness of the sin, and lifting of the automatic excommunication for securing an abortion from the local bishop or from any priest to whom the bishop delegated that authority. The only "news" in Madrid is that hundreds of visiting priests have received that delegation for the duration of the event, to accommodate the great crowd present at the event.