That does not sound right. I am sure that plenty of kids with IEPs have been given regular diplomas, otherwise there wouldn't be all that fussing about the parents of perfectly bright kids seeking IEPs to get their kiddos extra test-taking time. I would want to consult other authorities if I were you.
My younger brother had an IEP from 1st-12th grades due to serious medical issues, and he absolutely received a regular diploma, was accepted to college, etc etc. I have never heard of an IEP impacting a student getting their diploma from a public school - in fact, that sounds like illegal discrimination to me. I would check with your school district or a counselor at your child's school, they would probably know.
Nope, not correct . IDEA is about ensuring access to the general education curriculum in the regular education classroom to the maximum extent possible, not prohibiting SE students from receiving a regular diploma. If your child meets course standards (even with an IEP ) then he gets a regular diploma. It's always a good idea to verify these things--I was told by my ds' school 1st-that I could not see ds' evaluation prior to it's presentation at the IEP meeting, then that it was up to the evaluator whether or not I saw my ds' evaluation prior to the IEP meeting-- I emailed them the text of the federal statute and a link . My state's law actually states that they have to provide it to me 3 days prior to the meeting.
"Wrightslaw: From Education to Advocacy"
"Wrighslaw: Special Education Law, 2nd Edition"
"Wrightslaw: All About IEPs"