I think the point might possibly be, Knight, that they in the company are fishing around for extra income by letting you know you can buy extra (as you correctly pointed out) items of gear.
If someone relatively new (maybe even ex Ryanair or Easyjet who's used to paying for everything) gets the wrong idea and buys new shirts instead of one-for-one-ing the issue stuff then they won't mind at all. And maybe, just maybe this is the thin end of yet another un-lubed wedge you can feel nudging around your posterior. Wouldn't be the first would it?
Rose tinted glasses and all that, WK?
You've been quiet lately, anyway, been away on vacation? Half your luck...