A "Right to Work State" only means that - even if your company has a union - you can not be forced to join the union / pay dues.
There may be a state or two that considers itself right to work - but they can still make you pay dues - or still make you join but don't have to pay dues. I can't recall - which - all I know is unions suck.
At will employment really has little / nothing to do with right to work.
I got a job while in college with a company that had a union.
I was 20 years old - had no real opinion about unions - good or bad.
After my interview as I was leaving - several employees were outside on break. One ask me "how did the interview go" I said pretty good - but you never know.
Then I was told - if you get the job and know what's good for you - you better join the union - if you don't your car will get keyed.
I never liked it when someone told me what I had to do under threat-
I told the guy to F off and he made a move at me - his friends stopped him - good thing I would have beat the everliving snot out of him.
I got the job - never joined the union - my car did get keyed - I eventually did end up beating the everliving snot out of MR Union organizer.
Strange - if they would have just left me alone I may have joined -
So in a way they did me a favor.
Hard for me to understand how any law could be passed that requires you to join an organization and give them part of your paycheck - it is just wrong.
BTW - in case you have not figured it out I am anti-union - in the same way the Pope is anti-abortion.