They are in a public square, not a church.
Ukrainian, not russian.
I don’t think Christians are required to vandalize statues in public parks to gather in them.
Anyway, it is not a Christian event in that pic, St george ribbon day is more like veterans day of remembrance to appreciate ancestors sacrifice. It was started by journalist to remember WWII dead.
There are a lot of people in ukraine who are not Christian. Those sympathetic to communists are not such a small percent.
Sadly what this rise in persecution shows is that Russia refuses to acknowledge the millions of Christians who were killed due to Lenin's policies and Stalin's Gulag camps.