To answer the OP's question,, no,, I do not think it will dry up anytime soon. A lot of people have 480's now,, and they are made by different manufacturers. So, as such,, ammo should be around for a long time.
That said,, as noted,, reloading is always a way around the potential lack of availability. As you shoot factory ammo,, you acquire empty cases. A main necessary component. Next are the bullets,, and quite often,, bullets are available long after some odd calibers have gone by the wayside. But another option is casting bullets. Many folks cast,, and casting companies offer stuff like this as well. Availability again will be a non-issue. So component #2 is covered. And of course,, powder & primers are the most readily available items USUALLY that can be found. Unless we experience panic buying & shortages again.
So to answer JFB,, & his question about a plated plinking bullet,, I don't recall any of the plating companies having a 480 yet. BUT,,,, cast bullets,, powder coated are excellent for that.
Now,, the OP has asked only about factory ammo. And as such,, again, I don't think we'll see any shortages of such offerings anytime soon. And,, some have mentioned reloading as a way around this,, and that is the one thing that can stave off the lack of ammo while still enjoying a firearm.
I own a few Hawkeye pistols, in .256 Win. I enjoy shooting one,, and factory ammo hasn't been available in a LONG time. As such,, reloading is the only way I can enjoy an old, classic & collectable firearm. About once a year,, Hornady makes a run of the preferred bullet I use,, and as such,,, I try & purchase an ample supply. Brass is also an issue,, so I acquired the necessary dies to form brass from a different case. (Something that's done often for old & obsolete calibers,, and by wildcatters.)
My point to all this is we as shooters can always find a way to enjoy our firearms if we want to. And while reloading may not be an ideal option for some,, it is the way we can do it. If a person enjoys shooting,, and wants to shoot a fair amount of ammo frequently,, reloading will allow more shooting at prices much less than factory ammo in general. Many discuss the "savings" of ammo costs in reloading,, but what I've found is that reloading allows me to shoot much more ammo for the same money I would have spent on factory ammo. More shooting is more practice,, and more practice makes me a better shooter. I shoot 10,000 to 20,000 rounds of ammo annually in general, depending upon my plans & habits for that year. (Competition, practice, planned hunting trips, teaching etc.) If I were to try & do that with just factory ammo,, my expenses would be MUCH higher,, and I can assure you,, I would not shoot that much. Just last year,, I shot almost every day, 1 gun & caliber, 15-30 rounds for 4 months, just preparing for an upcoming hunt. My reloading noted indicated I loaded & shot over 2300 rounds of that one load. That didn't take into account the competition matches, the teaching, or any other stuff I shot as well. But that 2300 rounds of factory ammo would have cost me easily $1800-$2000. But,, I cast & reloaded my own ammo. By casting my own bullets,, which I use scrounged lead & such,, & already having the empty cases,, all my actual expenses came out to was under $250.
I share all this to point out that while reloading may not be for everyone,, (and it shouldn't) it can easily allow a person to enjoy almost any caliber, at any time, w/o worry of availability. And a side benefit is the ability to enjoy it MORE at a substantial savings as well.