I don't think we can say anything for sure... yet. There have been a few people complaining, but most of them couldn't come with any proof and a few who did post some videos are "meh". Hard to say if it's really an existing and most importantly "real" issue ( it might be possible that some ghosting in present under some "extreme tests" or when one is really looking for it )...
IR appears within a few days, weeks, or months after using the machine. At first things will be subtly visible and as time progresses it will be clearly distinct. Just let the 13" rMBP users a few weeks or a month of usage before they return to express their dissatisfaction. Also, since we are unaware of the command that determines which screen manufacturer the unit is, it's hard to say who has what.
Please notice that the massive thread is mainly about 15" rMBP IR issue.
It was started back on the 16th of June.
... with the 13" rMBP, people didn't yet figure out how to get the display information.
So we can't really talk about LG sucking or similar. We don't know if any 13" rMBP uses an LG.