Is it true what I have recently read that the Coptic Orthodox church is accepting cremation as an alternative solution to high cost of burial and lack of room in cemeteries?
I am not aware of what you have read. Who from the Coptic Church is accepting cremation now? Our Church did not change her belief. Cremation is not biblical, because since the fall of Adam, God's judgment was clear "Earth thou art, and unto earth thou shalt return" (Genesis 3:19). Note God said earth not ashes.