The Greek word for "shape" has had a longer history than computer science. I'll grant you the use in mathematics, since it's difficult to talk about geometry without talking about shape, so it's highly likely that even people like Thales were using it back in the day.
This is the same thing as people insisting that "theory" as used in science has somehow been co-opted and misused by laypeople. The fact of the matter is that a word that has had a common meaning for a very long time has been narrowed and specialized in a specific field of endeavour, and that narrowed meaning doesn't somehow invalidate the older meaning outside of the field.
Nobody uses the greek word anymore. It is therefore invalidated. Morphism is currently used in things more fundamental than geometry, specifically category theory. Look it up on wikipedia, it's official. This medium article is far away from official.
What gets me is that some designer out of nowhere can repurpose the word because it sounds cool. Seriously nuemorphism? This is the inception of a buzzword, created literally for the purpose of "buzz."
I have a new word, it's called "buzzology." The science of stealing legitimate words from academic fields and repurposing them to make your new "theory" or "design" sound much cooler than just a drop shadow behind a box.
How about Quantumorphism? All of the buttons and labels have fuzzy blurry edges, and you can't tell if something is a label or a button without touching it, and the act of touching it changes it.
This is the same thing as people insisting that "theory" as used in science has somehow been co-opted and misused by laypeople. The fact of the matter is that a word that has had a common meaning for a very long time has been narrowed and specialized in a specific field of endeavour, and that narrowed meaning doesn't somehow invalidate the older meaning outside of the field.