Which is actually a bad thing, if the height is legit. Reason being he will have a tougher time getting low to stop edge rushers. And if he plays inside, it will be much easier for DTs to gain leverage on a much taller opponent.
And being still in HS, he's likely to grow more. So you have to wonder how tall he will get.
I actually hope for once a kids height isn't right and he is a few inches shorter than listed.
It seems like the NFL covets these tall OT, 6'5" - 6'7" has almost become the standard especially the Left Tackles. You don't see very many 6'3" guys at that spot any more. I imagine it's b/c of the arm length the have. If he is 6'9" he's going to have a huge reach advantage against almost anybody he matches up against. If he can develop great technique and has quick enough feet he's going to be very very tough to pass rush against. Iowa is like an OL factory they seem to send quality O-linemen to the NFL every year. They must have seen something they liked in him to offer him. And who knows 10 yrs down the road everyone might be looking for that 6'8" - 6'9" OT.
Arm length is fine, but that would be beneficial for a shorter man to keep defenders out of getting into him. At Sterup's supposed height, defenders are going to constantly force him to prove he can bend and move. Edge rushers are going to dip their shoulder to get under his blocks. DT's will use his height as a disadvantage to consistently get under his pads to set him off balance.
Really, his best hope is at OT. Very few OG's make it being tall. I remember researching one that there are very few OG's in the NFL who are even 6'5 or taller.
Football is a game of leverage, and more times than not, the low man wins in that case. Being at an extreme height is a huge disadvantage in his case, and it's why most people at Sterup's supposed height choose other sports to succeed.