Yes, Gnus is ex(c)iting.
gnus-group-suspend). This doesn't really exit Gnus, but it kills all buffers except the Group buffer. I'm not sure why this is a gain, but then who am I to judge?
gnus-group-quit). The dribble file will be saved, though (see Auto Save).
gnus-suspend-gnus-hook is called when you suspend Gnus and
gnus-exit-gnus-hook is called when you quit Gnus, while
gnus-after-exiting-gnus-hook is called as the final item when
Miss Lisa Cannifax, while sitting in English class, felt her feet go numbly heavy and herself fall into a hazy trance as the boy sitting behind her drew repeated lines with his pencil across the back of her plastic chair.