My July 28, 2021 GC L Summit (5.7L Baltic Gray/Black top) just arrived at the dealer today (Nov 15, 2021). Actually arrived sooner than I expected. The build sheet showed all of the trailer package items were included, but the window sticker made no mention of any trailer package. First thing I checked on the pre-prepped GC L was the full trailer package with all wiring, 7 pin plug, and receiver; It was all there, so the GC L summits do currently have the trailer package as a standard item. Will know more tomorrow when I pick it up at the dealer after the prep.