Grain of salt, but from a reasonably reliable source:
Reliable sources are saying iPhone 11 and 11 Pro do include the hardware for bilateral charging, but that it is software disabled. Uncertain whether this was removed prior to final production run.
— Sonny Dickson (@SonnyDickson) September 13, 2019
This is the number one thing I will look for in the forthcoming iFixit teardown. Second is the battery size, as compared to the last generation models.