Comes around $8-11 of egress monthly traffic on AWS. I would think twice before signing up for a service that charges me $10/month - not sure why this should be any different.

Also, how do you opt-out? Imagine a random developer in a startup, running a Gitlab instance and then pushing a Go module there and only to be left with inexplicable traffic pattern(and bill). I have no skin in the game but this default _does not_ sound reasonable to me, whichever way you slice it.