If it were that big of deal, don’t you think Apple would have been forced to recall it and definitely couldn’t keep selling it for 3 years. True they did redo the antenna for the Verizon CDMA iPhone 4. But they never bothered to back port the changes to the GSM one.
I also had a GSM iPhone 4.
Compare that to how quickly they ran away from the shitty Intel modems when they were selling some made by Intel and some made by Samsung (?)