Yes, likely flexible copper. Likely it’s too long to fit in the shipping container so they bent it up out of the way. Be gentle as you tease it back into position, if you push it back in it might bottom out on your crossmember before seating on the mounting ears. You might want to trim it a bit with a tubing cutter.
What kind of radiator? If it’s a Brassworks, call them and ask what to do about it.