Hi Luisa,
Welcome to the AnyScript forum!
Generally, your understanding is right but the question is framed in a way that I can't give you a simple yes or no answer 
If you are talking specifically about the outputs that you see in SelectedOutputs, then what you are saying is correct. So, the reference frame that appears first in the joint definition gives the reference frame for the joint reaction force.
There is a way to see the joint reaction force in global coordinate system. To do this, you will have to explore to the joint. In there, you can find Constraints.Reaction.RefFrameOutput.M and F. These are expressed in the global reference frame.
And, normally, yes, the information that you find on the forum should be relevant despite the time. But, of course, it depends on the nature of the problem 
I would like to point you to a previous post, which is still relevant.
I would also like to point you to the wiki page where you can read more about this.
Best regards,
Dave