OK thanks for the explanation. Then perhaps the banner would be clearer if it said:-
“Do you know you can create a page in your blog used to display the sign up form? Go to the subscription panel to configure it.”
It would though be really useful to be able to have a way of listing newsletters. Obviously not just a simple list of all as not all newsletters may be for universal subscription. However if one could add short codes for newsletters that would be fabulous, say [newsletter-1].