You are correct. It’s an updated 3.6L with EGR and VVL. Although this updated engine is new to Wrangler, it has been used in other FCA vehicles since 2016. Just seems odd the part can’t be found unless the rear seal is truly unique for the JL.The rear main seal may be the same as the JK engine but lots of internal parts are much different, its the same engine but different.
If 68223854AA is the correct part #, it’s a universal item for all 3.6 and 3.2 Pentastar engines.