Re: possible reason we never seen the phaser rifle after w.n.m.h.g.b.
I find it easier to assume phasers were invented in the 23rd century, finally replacing all lasers in the mid-2260s, and that phase pistols are a product of a different universe.
That, and the phaser rifle was tested, then discontinued, and replacements were only fielded by units showing a need, such a MiliOps Command vessels, Marines, etc.
I don't see how the "different universe" rationalization is easier.
The boring one, the one with Khan, the one where Spock returns, the one with whales, the dumb one, the last one, the one with Kirk, the one with the Borg, the stupid one, the bad one, the new one, the other one with Khan.