Rather than wait for another with the same bike, to tell you ..
Make up something out of corrugated cardboard that is compliant and try it your self ..
or Find another carrier than Delta.. In-country tours , ship the bike Ahead on UPS.
The LBS , here, deals with Bike tourist's own bikes all summer. only a small fee ($10) to take it in and store it
if you write "Do Not Assemble", on the carton and DIY with your and borrowed tools when you arrive.