I wonder if JD's attorney knows about the .300 Ripoff I mean Blackout.
The 300 Whisper(R) and 300 AAC BLACKOUT are both versions of the 300-221 Wildcat. 30 cals based on 223, 5.56mm, or 221 Fireball brass have been around since at least 1969 (see photo below from 1969).
The 300 Whisper is a proprietary version, while the 300 AAC BLACKOUT is the SAAMI standard version, for which anyone can make guns or ammo royalty-free.
Since Remington makes a 17 and 221 Fireball, the logical name would have been 300 Fireball. But, because several wildcat chambers existed with that name, SAAMI either would not have accepted it, or would have required the most conservative chamber - which would have limited performance. Likewise, there are several Whisper chambers - and if there was an attempt to make that a SAAMI standard - the most conservative one would have had to be selected - and that would result in lower velocity than the 300 AAC BLACKOUT - which was a clean-sheet approach to making an optimal 300-221.
SAAMI is necessary - not just for pressure testing, but to ensure compatibility with any gun and any ammo with the same cartridge name. Also, larger ammo companies like Remington won't load wildcats.
You can shoot Hornady 300 Whisper ammo in 300 AAC BLACKOUT chambers, but not the other way around - as 300 AAC BLACKOUT is hotter - so shooting that in a Whisper chamber would be like shooting 5.56mm in a 223 chamber, or like shooting 6.8 SPC-II in a 6.8 chamber.
About 45 companies have announced 300 AAC BLACKOUT products.