Nowadays only Elbowlock is officially permitted in judo competitions.
Nevertheless, National federation (french judo federation in particular) has set up for 5 years Newaza competitions where ankle-knee-shoulder-wristlock are authorized.
You could remark that sometimes udegarami turns out to be shoulderlock even in international slam.
But let's come back to wristlock and modern judo. Actualy, when tori in competion (even Paris or Duseledorf) try to do jujigatame, he practices a hidden wristlock to free uke's hand from his judogi. That's the reason why Judo french team trains to avoid wristlock by leaving no room between the harm and chest when defending jujigatame. I talk about hidden wristlock because if you practice with your right handle a wristlock on the right wrist of your oponent, you can hide this bad gesture (from the eyes of referee) thanks to your left handle.