they probably didn't redesign it in the sense of 'secretly fixing the great big design flaw' because there wasnt one. But folks will read into any changes as being that kind of fix
Yes, there are some real sore heads that insist, months after the fact, that Antennagate was a BIG DEAL for Apple, even though the sales rate shows it was a minor blip driven more by bad PR than bad technology.
Yes, Steve admitted there was a problem, so quit pretending he's still trying to deny it. But what Steve pointed out is that it was simple physics that potentially affects all phones to one degree or another (though the dead spots will vary due to differences in antenna design from phone to phone).
That's why the original iPhone 4 continues to sell well despite this supposed "defective" design (that isn't defective).
Naturally the antenna design will change in the future -- it always does from year to year. No need to run around with your head on fire yelling "they are admitting they made a mistake!!!" They're doing nothing of the kind other than trying to improve a product with every new iteration . . . as always.