Pavlos goes to Greece regularly, I think more than before. I think Pavlos' eldest son should also go to Greece more often, as he is the future head of the royal house.
But the relevance of the royal family among European royalty is assured, as they are close to almost all reigning royal families.
They are close now mostly because of their kinship to the Danish, Spanish and British royal families. But will they be two generations or so from now? Will Princess Leonor's children, or Prince Christian's chidren have a relationship with the children of Prince Constantine-Alexios? Will Prince George's family in the United Kingdom have any relationship at all with the Greek royals?
If you look at royal events today, the only former sovereign families of Europe that are consistently invited are apparently Bulgaria, Greece, Romania, and Serbia. Dynasties that are much more prominent (historically speaking), but whose degree of kinship to the current sovereign families is now very distant (maybe centuries removed) tend to be overlooked. My feeling is that, unless someone in the younger generation also marries dynastically, the Greek royal family will slowly fade like the former ruling families of Austria, France, Italy, Portugal, etc.