I too, am curious. Does anybody know when the oil consumption issues were truly resolved, if ever? Looking at reviews, complaints seem to die down a lot by the 2016 model year. I saw someones post about new rings some time in 2013, however I still read of complaints up to 2015 (with oil consumption).
The oil consumption issue was addressed but not necessarily "resolved" after 2014 with the design of new piston coating and ring design. That said , we have seen one or more 2014 owners here cite oil consumption in there 2014 engines as I recall.
Was it because of design failure or lack of owner proper maintenance (oil and filter changes, correct oil as per GM spec, etc)?
Again. . there was no TSB (Service Bulletins) and no documented design changes regarding the 2.4L PCV issues that have the potential to cause a main seal blow out.
Not seeing any 2016 or 2017 2.4L main seal blow outs is no proof they can or won't occur.
There were no 2013, 2014, or 2015 main seal issues initially until the last 2 years or so when some owner posted here. Simply because it took a couple years for the PCV orifices became partially or fully clogged with deposits and/or frozen with moisture build up in the crank case.
The potential for 2.4L PCV orifice clogging or freezing still is present in any and all 2010 to 2017 2.4L GM engines. And there still seems to be a potential for oil consumption at least from the one or two 2014 owners that have experienced it and reported it here.