It's been a year maybe more. I am not sure they are looking into it.
I definitely think they've looked into it. Whether or not they are still working towards a solution is debatable. There appears to be some feedback recently from Tesla SC that the Windshields are within specification and they even have some testing equipment to verify that.
While these windshields may be legally within the tolerances dictated by law, I think those tolerances are way too lenient. My personal windshield has noticeable ghosting and while it may cause increased strain during night-driving (I haven't done a lot yet), I wouldn't say it's a big safety issue.
However, I can imagine that with a slightly worse windscreen and for someone who does a lot of night driving behind cars with LED tail-lights, it can be a safety issue.
At this stage, if Tesla is quoting standards and being within spec, it doesn't sound promising that there will be a large-scale recall or windscreen replacement. Perhaps (this is speculation) their manufacturer is refusing to recall (under warranty) these windscreens because they are within spec. and Tesla isn't in a position to pay for a total replacement out-of-pocket.
I just hope that long-term they are working on a better solution (either internally or by switching manufacturers) so that they can provide a better product. Tesla is always (quietly) making improvements to all areas of the vehicle and rolls them out as soon as they are ready. So, I wouldn't be surprised if one day the windshields have significantly reduced ghosting.
I would still recommend that all customers with bad ghosting complain to Tesla.