Press Conference & iSpin
Well I suppose the two likely outcomes, this being Apple, that they're really going into denial and hope to tell the press so loudly that there is no problem that they'll believe them.
Or, they'll state categorically that there is absolutely no problem with the Iphone and nothing needs to be fixed or changed... however, because they're such a wonderful loving company, they've decided to take a massive financial hit for absolutely no reason and replace all shipped units purely to allay the unfounded fears of their valued customers. See what nice guys they are?
Of course... despite the replacement units being absolutely no better than the perfectly fine units they're replacing already were, they'll have much less of a problem with the antenna.
Note that I said 'much less' and not 'none'. If Apple do change the production process, it'll be a quick fix such as coating the antenna with magic paint rather than repositioning or redesigning it.
I wouldn't even put it past them to employ a Chinese Suicide Factory™ to whip peasants into standing next to a tin of magic paint and, using a cheap brush, paint the antenna of returned units for sale as 'nearly used' at a 30% discount.
Oh, and if there is a recall, be wary of any future Apple sales figures. Will their official figures include the combined count of returned and replacement units, effectively doubling the number?