As you probably know, many (perhaps even most) US distillers have been in the midst of a huge expansion in production capacity.  BT alone has built enough warehousing for over half a million additional barrels, and they are not done yet.  I haven't done the math, but if after 6-10 years of aging, if there are about 30-35 gallons left to bottle, that's a sizeable amount.  

Add up Beam (over 100 rickhouses), Heaven Hill (over 50 rickhouses), etc., along with all the smaller distilleries, and there's a whole lot of whiskey coming out of KY and IN alone.    

So my question is, what do you think the supply will look like 10 years from now?  Will "allocated" bottles be something we laugh at?  Will Makers have to release a 12yr bottle because so much product is sitting on the shelf, not moving?  Or will international markets develop a taste for it and completely absorb the additional production?

there's a huge supply of grain alcohol being produced everyday in Iowa. The ethanol plants run 24/7 and ship by rail. Not all of that goes to automotive fuel.

Trainl;oads of whiskey everyday. Many of those "distillers" simply age pure grain alcohol.

I hope in my heart of hearts that the production increases result in normal availability of currently hard to find stuff, but I have a feeling international demand will absorb much of it. Europe and Asia seem to have healthy demand for this stuff and I have to imagine that is where much of it will end up. I hope I'm wrong though...

How much of the Distilleries expansion(s) are standard growth or oh shit we fucked up and didn't plan well enough ahead.  Most distilleries make a bunch of stuff that is fairly easy to find with an occasional limited release that you might have to hunt. So I think most of them are doing the standard growth expansions, and are generally keeping up with the demand. The craft distilleries will continue to pop up and some will probably be successful and some won't.

The "Oh shit we fucked up" I leave that one for Buffalo Trace. You can find regular Buffalo Trace fairly easily around me. There are times it is out of stock, but go down the street and they will have cases available. Now, everything else from them is pretty much non-existent and tough to impossible to find currently. But, did they actually fuck up or are they keeping stuff back to increase demand? Did they not plan ahead for the demand 6/10/12 years ago? Even when their expansions are complete and the product has aged enough years will we see it on shelfs everywhere?

I've read that they figure demand will eat up additional production, so little to no change unless demand comes down. They're playing catch up with projected demand, essentially.

That might end up as “whiskey”, but it won’t be bourbon or any kind of straight whiskey.

Alcoholic drink tastes and fads usually come and go in waves like the demand for guns and ammo.

Bourbon makers are often faced with trying to respond to these shifts in demand years out and can either be caught short or left with a glut of unsold whiskeys.

I have heard stories of distillers putting what would now be considered premium 8 year old bourbon in their bottom shelf products simply because they had ran out of rack space and needed to dump barrels.

The Beam ceramic decanters of the 70's and 80's were an effort to increase demand and get rid of unsold whiskey.

So if bourbon continues it's rise in popularity and demand remains strong look for premium stuff to still be hard to find.

If tastes or fads change look for another epic glut and cheap prices and increased selection similar to the gun and ammo glut during the Trump slump.

I have never ever heard this, and I've done a lot of work at ethanol plants.
The denaturant is mixed into the ETOH at point of loading, so I guess it's possible but I am very doubtful.
Ethanol plants go through a lot of work and expense removing water to get to the final 190 proof.
I Can't imagine they'd do that just to have it mixed back down.

Allocations are not market manipulation by the distillers. They bottle and ship everything to their distributors. The distributors are the ones who determine what goes on allocation. They use it as a weapon against the retailers to make them buy less popular products. In Oklahoma we used to have multiple distributors who could represent all of the product lines. Then when the people voted to have cold beer in liquor stores little did they realize that they killed the competition and now we have two distributors representing all of the major bourbon distillers. Their reps hold the products in their product and reward their best retailers. In those markets it's feast. In all of the rest it's famine. And none of it can be blamed on the distillers.