I have to say though that although this agreement is only limited to Egypt, I think it's being used as a precedent in other countries. Here in the US, a GOA man and a Coptic woman were getting married, and I think they have made similar concessions in agreement with the bishops.
These things are indeed small, but I think concessions mean almost nothing if a couple is to be devoted to one parish. Yes, it's nice, and it brings unity (and I certainly don't mean "nothing" that this is not important). But if one is limited to one parish and is devoted to that one, I'm sure the intermarriage is not an impediment to being a priest, especially since both are "Orthodox" and both "should" be devoted only to that parish, regardless of jurisdiction.
Now, being a priest in that specific parish, usually it's very hard for priests to go to other parishes (let alone other jurisdictions) and pray there. Practically, perhaps the priest and the wife will stay at the parish they serve regardless of their allowing to commune in others or not. I don't think this should limit his becoming the priest, but the question of intercommuning is an interesting one. If intercommuning is to happen, it would probably be between the agreement of two priests and congregations coming together in one church in some sort of special inter-Orthodox liturgy, or if one priest has to necessarily substitute the other who is to be absent for some time, (so long as that priest's parish is covered by another who serves with him) which means certain bishopric permissions, that is if he even knows how to pray in the Liturgical style he's substituting for in the first place.
At this moment, this is not happening significantly (if happening at all), so we may never really know until perhaps next generation of Orthodox believers. Hopefully, this gets resolved if full unity is restored.