I think you may get more of a response if you post this in the main forum. I hope that maybe what I can contribute here will help you in some way.  I had the sleeve, not rny, so I do not know that much about the emotions after rny. However, since there is malabsorption with the rny,  there may be a possibility that her vitamin levels may be low, which may cause mood swings. She may also be having mood swings because she may be depressed because she can no longer eat to cope with everyday issues.  Also, she may be experiencing the loss of food. A few days after my surgery, I went to the supermarket with my husband, which I always enjoyed. As we got near the bakery, I started feeling very sad, because for me, I know I can not eat that stuff anymore, but I still was tortured by the delicious smell. Now that I have lost well over 100 lbs, I am not so tempted- but now I get upset over the shape of my body. When I was this weight before ( I was much younger), my body looked great. Now everything has fallen down and I need plastic surgery- which I never, ever thought I would even consider. Now the issue is- how do I pay for it, is it safe, how do I find a dr I can trust , etc. etc.. Losing weight solved some problems- but created others- and I can NOT eat over them! Is she having a depressed mood generally or is she acting moody with other people?  I certainly do not know your wife, but I have been married 30 years. Sometimes, when a person has been overweight and then becomes thin, that person gets a lot of attention from the opposite sex. Maybe she has found other friends, and she picks a fight with you, in order to get out of the house, and meet up with other people. I think you should suggest maybe doing a weekend thing, where it is relaxed, and say something like, "you know I am so proud that you have been so successful but I feel that we are not as close as we were before. Are you happy? How can we get things back on track"...don't blame her or tell her she acting moody, or she may turn you right off. Good luck. 

You may want to check her BS when she gets like that. Many post op RNY - we get RH  - reactive hypoglycemia. It can be ugly.
Also hormonal issues may play a role.
But - as long as you excuse that behaviors and allow it to continue - she does not need to do anything.
You need to sit with her when she is calm and talk about it. Even with hormones and sugar issue s- we do have control what we say and what not.
or maybe she has metal issue? like bipolar? maybe she needs to get evaluated by a professional and gets on medication.
AS long as you tolerate the verbal abuse - it will continue . She will change only is she wants to.