Update to my saga:
So I ordered three cards on each of three separate Amazon accounts (2 are mine and 1 is dw's). On my first account, it appears that all three orders are fully intact. On my second account, all three spa GCs got cancelled but they left the Amazon GCs. (Thanks, Amazon.). And on dw's, they cancelled 2 out of 3 spa cards but left one intact. They also left all three Amazon GCs (thanks again, Amazon). So I may still walk away with 4 spa cards. Pretty great if it comes through.