FA here, too (LANCE & 105mm), and that had me bumfuzzled as well. I’m marking it up to the usual reason: so few Americans serve today that the typical “journalist” doesn’t know the difference between ADA and FA, only that they both say “artillery.”
On the bright side, I’m glad to see that the HI-MARS is being used to achieve better stand-off and striking power in these efforts.
That confused me, too. 1st Bn, 10th Arty, RVN '70, '71.