If the clipboard content is a valid link, it should be the default text when pressing Ctrl+K in notes. Then it is a single action: pressing Enter.
As it is now, there is an extra step after Ctrl+K : you have to first paste from the clipboard, then click Enter.
If the default (clipboard) text is not what the user wants it is a simple matter to either (a) start typing, thus overwriting the default text from the clipboard or (b) paste something previously recorded in a clipboard manager like Ditto - again overwriting the default text.
Either way, if implemented, this change should not inconvenience anyone.
This is very useful and efficient in other programs.