Pretty sure the Atmas are more of a reference to FFXI since they were obtained in a similar way (defeating high level monsters) and while they weren't applied to weapons in XI they were applied to your character in certain zones (had a capacity to equip 3 at a time). Seems like they'll be used for weapons this time around in FFXIV along with a nice touch of mixing it with a reference to FFT's lore of the Zodiac Braves. Really nice to see them reuse the name Atma of the Lion though since it dropped off a Elsamoth (Behemoth variant) in FFXI named Hadhayosh. Doubt that means anything as far as what drops it in FFXIV though.

I just hope there's no need to proc Red for these Atmas to drop lol.