ED2 is exactly designed as a back up plan. If it was first choice it would be ED1. I’m surprised to see veteran posters questioning this. It has been forum wisdom for the entire time (forever, I think) that I’ve been here that a student can change their mind about ED BEFORE the acceptances come out.
There’s nothing underhanded about it, and I don’t understand why a HS would make that determination to not send them out, unless the ED school explicitly forbade a concurrent EA application. Many do not. It’s out of bounds for a HS to make that call.