The "Falcon" name dates back to many years before the BFR concept. Then the BFR started out as "Big Fucking Rocket" and the F was retroactively changed to Falco

The "Falcon" name dates back to many years before the BFR concept. Then the BFR started out as "Big Fucking Rocket" and the F was retroactively changed to Falcon as a tongue in cheek way of keeping the acronym in respectable conversation. That said, BFR was always just a descriptive placeholder.