I think this example needs more details. It writes "This function exists in another GPL-3 copy left licenced project" - does that imply that the project which copies the function and then goes open-source at a later point in time will also be released under GPLv3?
On the other hand, releasing the project, including a piece of code under GPLv3 and then marking the project as MIT would be an infringement, seeing as MIT is less strict than GPLv3 about permissions.
https://github.com/phuse-org/E2E-OS-Guidance/blob/0891e63f439b09c84963c00890fa04962e793a3c/releasing.qmd#L55
I think this example needs more details. It writes "This function exists in another GPL-3 copy left licenced project" - does that imply that the project which copies the function and then goes open-source at a later point in time will also be released under GPLv3?
If that is the assumption, then they are not necessarily in the wrong as per my understanding (is the original project attributed and referenced explicitly?): https://fossa.com/blog/open-source-software-licenses-101-gpl-v3/
On the other hand, releasing the project, including a piece of code under GPLv3 and then marking the project as MIT would be an infringement, seeing as MIT is less strict than GPLv3 about permissions.