Short answer is: Yes.
The status of the metal cans was changed in the DRMO process (that's Defense Resource Mobilization Organization, which handles all military excess). Ammo cans changed from Dispose at Will, to Retrain if Servicable. Part of that is the slimming down of Mil contracting, there's not enough margin to let your subs make long over-runs, and just dump the excess. Mil has adopted the "use the cans for everything" model ans well, too.
It's been decades, but the days of being able to go to the Ft Polk, or Ft Hood Surplus Sales and go get a truckload of stuff in bulk have long faded. That's how history goes.
The dumb part is that, "cans are local." Because they are both heavy
and bulky, nobody wants to shift them unless there's a serious profit in doing so (current fuel & shipping issues have not improved that at all). Let's say a person stumbled on a trove of say, a hundred. Ever stacked a hundred ammo cans in a trailer or the back of a truck? It's not intellectually taxing work. But, who ever wants them gone, wants them gone
now, not later.
So, you now have a hundred ammo cans. Ok, you got them for the trouble of loading them up and taking them away. So, maybe $5 each is fair. But, if shipping is $8, what is the fair price then? Or when shipping four cans is not $32 but $45 as it's a oversize/bulky, what then?
tl;dr--it means here, there may be none. There, there may be plenty, but they are almost as spendy.
Guy I know has been in the surplus biz a long time, a lifetime. He knows a guy, from when he was young who has a barn or "warehouse" in the Belton/Killeen area not that far from Ft Hood, who is holding onto thousands of cans in crates and cardboard boxes, that the old coot was unwilling to shift, back when labor was $2/hr. So, all the folks in the surplus biz know the cat, and they are all waiting for when he goes to the Great Beyond, as, when the stash is found and broken up, it will depress the ammo can market, for probably all of about 4 weeks