This whole case is very likely much simpler than presented by the media spin machine.
If everything happened as reported then the couple must be currently living without sexual intimacy for the Holy Father (or any Catholic clergyman) to say that they could worthily receive the Holy Communion.
In such case it is advisable for them to go to a different, than their own, parish to avoid giving scandal to those who don’t know the details of their situation.
I know of more than one situation just like that.
It amazes me how impetuous our dear Papa is compared to the other six pontiffs in my lifetime. It seems to me the job requires a little more circumspection.
This couple has been civilly married for 19 years and have two children. It’s not very likely they are living as brother and sister.