Hello,
Yes, you've read right. Instant respawn in PVP. Kind of, actually.
I just died right before being bumped on a bg. I clicked on the respawn button while in the air. It made me respawn instantly where I was before I die.
So it could be used basically to instant respawn. For exemple when you see you're gonna die you go near a bumper and get bumped before dying, or something like that. I don't know exactly how to use it but I think this has a high potential.
It happened to me only once, need confirmation.
Edit : Just to add more precision :
If I remember well, I have been bumped by a spell (don't know which one).
So I don't know exactly how this thing work but I guess there is something to look for arround dying while under a control effect. Maybe there is some effects that makes this exploit possible.
Then it will probably be possible to find a way to "really" use it. For exemple I think of spells like the jetpack of some classes.