Haven't purchased car yet. Still researching and doing due diligence.FFS..enjoy your new car. I don't think this is a widespread TourX problem and can't recall any member so far that has these issues on 2018+ Regals.
As to long term reliability...who knows for sure..but in general the 2.0T has a fairly good reputation and has been used extensively for a number of years in multiple platforms.
That was a oil issue using sytheiric blend. GM only uses full synthetic since 2017. We have the current sparkplugs too.