True! And when you look at the history of mankind, that’s the way it works! The morality of yesterday is completely different today! Even with religions! In the USA Christianity was used to justify slavery; today’s Christians will call it a stain on the country, and claim the Christians of those days were disobeying their God. And yet most religious scholars of today claim the baby Jesus was born of Mary when she was between 11-14 years old. With today's morality such a young child giving birth would be considered immoral! When you look at issues like interracial relationships, Homosexuality, human sacrifice for religious purposes, rules of war; it is clear that even within the religious community there is a constant change of morality even within that community. Heck even with Gods! Look at the difference in the Bible between the God of the Old Testament (Yahweh) vs the New Testament (Jesus), look at the way Yahweh instructed to treat one’s enemies (Numbers 31:18) vs the way Jesus instructed to treat your enemies (Matthew 5:44) even though they are supposed to be the same God, their moral are obviously much different.
Now I hear many Christians will compare acceptable morality of yesterday to today and they claim they were wrong then but they’ve finally gotten it right, but I will bet in the future, they will look at the morality of today and claim we are wrong today, and whatever moral beliefs they have at that time is the right one.
So YES! Morality is in a constant state of change, and many things considered morally acceptable today will be found to be immoral in the future; and visa versa.