So the Constitution class had never shown dorsal phasers. Assuming TAS is canon, they do. I'm not trying to open up Pandora's Box, but isn't TAS not considered canon?
TOS never showed
the port, starboard, midships and aft phasers, either. Are you asking if the ship has a giant blind spot shooting upwards or are you just trying to pin down where the phaser emplacements are?
Port, starboard, midships and aft are mentioned, being mentioned means they are there. Where exactly is the question for those phasers. You, I believe, brought up they were mentioned in dialogue.
TAS would seem to be canon, or at least reference material; or "Questionable Canon" as Memory Alpha puts it in the links previously provided.
However, In A Mirror, Darkly
only showed the ventral phasers and the aft phasers providing dorsal shots. The Defiant in that episode even tilts to one side to fire torpedoes at the ship attacking her dorsal side. If there was ever a time for dorsal phasers on the saucer to fire, that would have been the time.
So yes, where are the emitters?