I'll skip past the fact (that's horribly obvious to almost anyone who reloads!) that those SOBs are already making small primer .45 and simply comment on the idea of it.
At it's heart, it's a fine idea... the problem is that we've got 106 years of .45 Auto brass on this planet that already has a large pistol primer.
It's much more than a simple annoyance. What it truly is it a pitfall/danger for anyone who handloads because when you use tools to prime a case and you expect a large pocket and you attempt to fill it with a large pistol primer BUT it ends up being a small pocket, you are begging for a discharge on the press (or other tool.) That's noise, flash and maybe some flying metal, and you've gotta hope there is no chain fire.
All this hazard for what? Would have been fine if not for the fact that we've already got 874 guzillion pieces of large primer .45 Auto floating around.
One round that could really benefit from a small pistol primer over a large one is 10mm. The spot between the extractor groove and the primer pocket becomes the weakest part of the brass and getting 10 brass to run smoothly in a tight shell plate is a horrendous problem for me when the stuff it even slightly out of spec -- because of that large primer pocket.
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.