I started as undeclared engineering in fall of 2001, so no idea if this is still the case at ISU or how it compares to Tx Tech. However, at that time the first programming class you took (160-series classes, I think) varied somewhat depending on major, and I seem to recall that class was a prereq for certain 200/300 level classes in each engineering discipline. I believe I declared EE after first semester and took the programming class spring semester, and still made it out in 4 years, but I seem to remember there being some limitations of what classes I could take in my 2nd semester vs if I'd taken a programming course in the fall. Or maybe I took a generic one instead of what an EE normally would have taken and had to go through an advisor to register for stuff later because I didn't technically have the correct prereq... it was long enough ago I can't remember for sure, but I know there were some slightly weird wrinkles. At that time most of the core requirements were the same for all the engineering majors, but I think there were some other nuances (like I believe ChemE had to take a different/harder chemsitry than most of the other disciplines).
So basically where I'm going with this is, if he has some inclination of what major (or majors) he thinks he's most interested in, I'd look kinda close at the 2nd/3rd/4th semester classes and see what the prereqs are to make sure there isn't anything that could become limiting. Or at least be aware what could become limiting and make sure there's a way around it.