We're saying that it's incorrect to call Mary the Mother of God.I don't see Jesus morphing into a different form as diminishing him. The only thing that did diminish in that morphosis is he voluntarily diminished his equality with God, refusing to exercise the power and rights of that position he surely has in order to become a faithful and merciful High Priest acquainted with the plight of mankind, and thus able to sympathize with us and help us. He surely did condescend and diminish that way. To God's glory.
That would mean she did not birth God.
Any form of God.
That would mean Jesus is not God.
This morphing thing is something I've never heard of and am not sure it's doctrinally correct.