Maybe ya'll already know this, or don't care, but here it is anyway.
The other day I re-booked our July 27th Vegas RT flight, three of us. Being unsure of when we wanted to go I picked the first week in October. A shot in the dark. The only reason I thought I should re-book was to not lose our Early Bird money, $50 each.
Uh, oh, next day got the dreaded "Your revised itinerary" email, here we go again. The revisions (by SWA) made us change planes both ways. No no. Must try again for a non-stop.
Turns out I had to call SWA since THEY had revised my itinerary. Couldn't make the changes online.
OK, here it comes, the EB refund part. After the agent got our new flights done, she said "OK now I have to refund your Early Bird(s) to your card and then make a new charge to put your Early Bird back on." She is apologizing for the additional time this takes. Suddenly I woke up to the fact I could get EB refunded on these flights which we may end up cancelling anyway! I asked if she could just do the refund and forget the EB for now? Yes! Score! I can always add it back on later if we go.
So, it appears if you use the SWA call center to re-book, and you had booked Early Bird with the original flight, since that is a separate transaction the agent has to refund it to your credit card and do a new charge to put your EB back on. If you want the EB cancelled the agent can refund the $50 and not do a new charge.
I will assume, but not certain, that this applies any time that you use the SWA call center to re-book or cancel a flight. Worth asking about if you are ever in that situation.