The "gooseneck hold" as taught from the escort position when the armbar is resisted by the subject attempting to curl out of it can and does work in that context, you escorting a subject and them passively resisting by curling and pulling away from you.
However, I have yet to see one MMA fighter escort another fighter around the cage.
Most TMA's teach the majority of their locks from static assaults, IE, the guy comes in with a punch and stops while you deflect and catch their wrist, then step into a wrist lock of some variety while the attacker stands there and lets you. Or the most common attack in almost ANY dojo in america.... the dreaded wrist grab and stand there while they lock you up.
While you can get some of the traditional wrist locks to work, you can't do them the way most schools teach them. Too many never get past the introductory teaching phase of a student sticking out their arm and letting you lock them up. If they aren't doing it in unrehearsed free sparring, then the locks are worthless to that individual. Very few schools I've seen teach locks where they work best from, the clinch with a lot of body contact to off balance your opponent. Think of it as Judo Kuzushi with Jiu-Jitsu or Aikido locks. It's ugly, and "bad technique" as I was told on many occasions, but it works.
In BJJ or any type of submisison grappling, the wrist lock is a lot easier to apply since you can grab the hands and you aren't hampered by wraps and gloves.