Yep that is what I was meaning thanks for checking thatYou said all I/O shield are the same size. Nobody except YOU said ANYTHING, at all, about an I/O shield. So before you try correcting somebody, get your own business correct first.
And I/O "shield" is the metal piece that snaps into the back of the case and matches the specific in/out ports on a per model of motherboard basis, like this:
What the OP is worried about interfering with the CPU cooler is the I/O "cover", which is THIS:
So again, you're just making yourself look silly by arguing.