This is interesting. I was wondering what would happen if the EP responded this way.
So what now? Is a council necessary to resolve this now, or is everyone just hoping that the EP will see how many other jurisdictions are siding with the MP (Alexandria, et al.) and rescind his previous recognition of the independent group in Ukraine?
It seems a council would be
nice, but I assume that the Patriarchs are wary after last time (in 2016, when not everyone attended). If we did manage to convene a council of all the autocephalous Churches (we weren't invited last time because our autocephaly is not universally recognized, but we helped with the council), or all the effectively autocephalous ones, one major danger is that a powerful jurisdiction just wouldn't like the decision reached and would either go into schism or just declare the council fake.
So, I don't know what everyone is hoping. I certainly can't speak for the Patriarchs involved. My guess is that a lot of people see this as a political spat and are hoping that by not exactly formally taking sides -- by breaking with the EP or the MP -- they can just wait for it to blow over.
Personally, I think that the most desired outcome of this for political folks in the Russian Federation -- so I'm not talking about clergy here, I'm saying what I think would be desirable for people not in the Church, but to whom the appearance of a "church of empire" is politically useful -- is roughly the following:
Serbia and Antioch and a few other Churches break with the EP. After a while, the MP issues an ultimatum - break with the EP or we break with you. The Churches that sided with the MP do the same. Schism. Then they can hold a council that will put Moscow in the place of the EP. Politically useful, and state and Church organs can say that "the Greeks" and "the Westerners" abandoned the Orthodox faith, that will become a standard thing to say, and they can claim that only they are Orthodox. Then this is useful politically -- "we" (i.e. - the former Soviet bloc and some friends) are the guardians of Orthodoxy, etc.
We'll have to see what the other Patriarchs say, of course. But regardless of statements and thinking this or that action by the EP is undesirable - if no one breaks with anyone, then Moscow is in the unenviable position of having removed itself, sort of, from the fullness of the Church. And how they would handle that, of course I don't know.
They could just let it alone for a few years, and eventually the Ukraine situation will be sorted out to the satisfaction of everyone but the MP. In which case we'd have a (likely autocephalous) Church in Ukraine that only the MP thinks is schismatic. And a generation later, no one will care and eventually that Church will be recognized first de facto, then officially.