Sounds dumb... but matching hardware and webbing is often the bane of the DIY/MYOG pack builder. It's shockingly easy to mess up.
If it was a personal pack of mine... I have helped/resolved that issue by running rows of stitching into the webbing with the sewing machine to help bulk up the webbing at the buckle a bit if you have that option.
Come in about a 1/16" and then sew 1/8" parallel rows of stitching on the width of the webbing, about long enough to cover your personal range of adjustment.
But assuming you paid money... Joe isn't exactly a rookie cottage guy in his basement so I'd figure it's his solution to provide unless you wanted to attempt repair yourself if you otherwise are happy.
Guess yer glad you got that Osprey fer now.