***(I suppose I'd better preface this with a SPOILER ALERT )***
Yep, that was it exactly. I wanted the +1 weapons there so the party would have something to fight the coin dragon with, but at the same time I didn't think that justified giving them to the party permanently, especially since the adventure was intended for low-level PCs. Also, I tried looking at it from Gorgoldand's perspective: I could see him giving away Hoardmaster after Hoardmaster (since he derived a personal benefit from doing so), but I didn't see him passing out these other +1 weapons left and right.
I chose the specific weapons I did mostly because they were fairly unusual, and I figured it was a chance for PCs to mess around wielding something they might not normally choose as a weapon. (After playtesting the adventure, my youngest son decided his monk would wield a pair of siangham on a permanent basis because he thought they looked cool.)
Another benefit (at least in my eyes) was that I suspected most PCs would choose these new weapons as their primary weapons (assuming that these newbie PCs probably wouldn't have magic weapons up until that point), and that they'd have to sheath their weapons to climb back up the rope outside the Gauntlet, so when they were ambushed by the bandits once back topside I imagined there'd be a bunch of startled expressions on the PCs' faces when they go to pull out their handy new weapon only to find out it's no longer there!
Johnathan