Celibacy is now a discipline of the church, not unalterable dogma.
Of course, yesterday celibacy was a discipline of the church, not unalterable dogma.
And in 1600, celibacy was a discipline of the church, not unalterable dogma.
Etc, etc.
This is another of the many examples of the media reporting on something they don’t understand. In fact, even today celibacy is not an absolute requirement for the priesthood: there are married Catholic priests.
To say something “can be discussed” is to distinguish it from matters that are unalterable dogma and for which change cannot be discussed to any meaningful end, because it’s not possible.
This is what Archbishop Parolin meant, and he makes it more clear in the interview itself. Unfortunately this is in Spanish. But he says (my translation):
Q: Are there not two classes of dogmas? Is there unmovable dogmas that were instituted by Jesus and then are those that arrived afterwards, during the path of the church’s history, created by men and therefore allowable to change?
A: Definitely. There are dogmas that are defined and untouchable.
Q: Celibacy is not…
A: It is not a church dogma and it can be discussed because it is a church tradition.
What he says is theologically correct and unremarkable. The same thing was true last week, last month, last year, and last century.