If weight were an issue for Challenger owners, I doubt they would have bought one.and then have a Hellcat that's close to 4,700# (current ones are 4,450#)
I'd venture the GC AWD setup is bulkier and heavier than the AWD system the Challenger GT has (which is only rated for the V6 torque)
2018 Jeep Trackhawk Hellcat 0-60 mph Testing - YouTube
While testing the trackhawk, they got 12.0's for the 1/4 mile. Not saying they *fixed* the race so the hellcat would lose BUT you'd have to be a pretty novice driver to run slower than a 12.0's in a hellcat.
If weight were an issue for Challenger owners, I doubt they would have bought one.
They could beef up the Challenger's AWD system like they have the GC. However it would raise the Hellcat to Demon money.