So basically if the piece is good, you guys get a piece and the owner loses original rights. If it’s lousy, oh, gee, they can have all their rights back.
As usual, this is a fishing expedition for free content. Not impressed, not submitting, and I would warn anyone considering this option to think long and hard if you want to give away your material. If it’s that good, you should be able to get a publishing contract and an agent.