Further supporting RAW, pg. 258 CRB. Special Weapons, "Use the Exotic Range Weapon skill...." then lists 2 ranged weapons.
Pg. 118 CRB, for the Exotic Weapons and spray example, " ....Exotic Weapons (Flamethrower)...." which lines up with the previously posted example from Firing Squad
Followed by
"Launcher the Exotic Weapon skill is used to fire launchers...." listing both missile and grenade launchers.
pg 263 "...Exotic Weapons (Launcher)..." when discussing launching grenades from a grenade launcher
There are also several more examples of characters or references to either Exotic Weapons Launcher or Exotic Weapons Ranged.
The one exception that breaks from the Launcher being a group that composes Grenade and Missile, is pg 116, which is an explicit example given for Grenade Launchers. One could argue that this one example juxtaposed against the many other examples that contradict it, is explicitly referencing a "...Exotic Weapons (Grenade Launcher)..." due to it being an example on Grenade Launchers and was author/editor oversight.
Only real mention to an Exotic Melee Weapons group is in Firing Squad on page 14, as the header to a list of Exotic Melee weapons, similar to how Launchers was the header for Grenade and Missile Launchers in the CRB.