You're talking about designing and manufacturing entirely new guns. It really wouldn't be that easy or cheap to do, even for a hollywood production. Plus it would take a very long time. Normally, if you want to shoot blanks, you need a special blank adapter that attaches to the muzzle.I've thought about this quite often. With the budget behind these films you could easily hire a machinist to manufacture a picture-perfect replica of any firearm that can't accept live rounds and another expert to create turbocharged blanks that fit it. It's unfathomable to me that something like this can happen on set.

This is because a blank round does not provide enough energy to cycle the bolt on most autoloaders. From what I understand, with semi autos & autos Hollywood gunsmiths specialize in modifying them to shoot blanks without changing their appearance.
But since the gun in this case was a revolver, you don't need to do any modifications, so it seems like they were using a 100% real and functional revolver. This SHOULD be fine if they had a competent (male) armorer who followed all the safety rules. But apparently this fat chick was using the gun for live fire "target practice" off set and had stored the blanks with the live ammo.
It really just comes down to a case of womens' retardation. Did you see the tik toks she was making?
Would you trust this thing to tell you if a gun was loaded or not? I wouldn't even trust her to do my laundry.