You're getting downvoted while being right. A dark pattern is tricking the user. Not saving the data they enter. But most people around here call anything that is distasteful a dark pattern.
Yes, there are some settings panels that automatically save changes, but I have never seen it for forms.
If there's an submit button on that form then that would be an even stronger signification to the user that nothing will be sent to the servers until you click that button.
As I said, it is distasteful but not a trick.