That's really interesting, Tradd. The Antiochian parish I attend states specifically in the bulletin who can and cannot take communion. They certainly wouldn't let me participate until I am officially Orthodox, but it would be interesting to find out where they stand on Copts and Armenian Orthodox.
PS, you're an American of Protestant background! The "usual rules" are bent in many ways when it comes to those Orthodox from the Middle East.
Now, the situation I described - a Byzantine Rite Catholic woman marrying an Antiochian Orthodox fellow, both immigrants from the Middle East - if the marriage was taking place in the US , would be handled differently than if happening in the Middle East. The woman would not be allowed to take commune, be a godparent, etc., in the Antiochian parish *unless she actually became Orthodox.* I have this directly from the mouth of a priest from the Middle East. I asked him directly.
You might not be aware (Met. Kallistos Ware mentions this in The Orthodox Church), but in 1724 a large part of the Orthodox Patriarchate of Antioch submitted to the pope, apparently for the political protection afforded by being under Rome.
I've not seen anything online publicly from Met. Philip about communing Coptic and Armenian Orthodox, but I've been in a parish, where this happened several times a year, and the priest made a point of tellng parishioners that Met. Philip required that Antiochian priests in the US commune Copts and Armenians. Period. The only stipulation is that the Copts and Armenians be in good standing and practicing in their own church. I have a friend who is first-generation American, born of ethnic Armenian parents who immigrated from Lebanon. The family ended up in Lebanon after the Turks committed genocide against the large Armenian population in Asia Minor in the 1910s, and others fled or were expelled.
Anyway, my friend was raised Armenian Orthodox, didn't understand the liturgical language, fell away. Married an American woman in the Armenian church, but they became Evangelical Protestants. They became interested in Orthodoxy at an Antiochian parish and were converted. My friend's parents visit the Antiochian parish 1-2 times a year. The first time, the father was asked at the chalice if he had recently confessed in his Armenian parish. He said no. The Antiochian priest told him that if he went to confession at his Armenian parish, he could take communion in the Antiochian parish the next time he visited. And so he did.
This communing of Copts and Armenians, again, is ONLY for visitors. If an Armenian or Copt liked a "regular" Eastern Orthodox parish and wanted to join, they would have to become Eastern Orthodox. I know a Copt who became Orthodox, became a deacon and is now an OCA priest. He and his wife are immigrants from Egypt.
BTW, there's a large Coptic parish near me, and I'm told the food at their Egyptian fest is fab. I have to go, given my addiction to Middle Eastern food!