... or it might get worse!

Potential informants, no longer trusting the US to be able to keep their identities secret, clam up. Intelligence dries up. Bombs go off. People die. Dogs and cats living together. Mass hysteria.

What evidence do you have that that is actually what will happen?

The point is that leaks of this magnitude have much broader effects than you can imagine. You can argue about whether it is a net positive or negative, but there WILL be negative consequences and to pretend otherwise is just fooling yourself.

I think it's fooling yourself to claim that you have any idea as to whether this will affect future informers.

It's also a matter of whose perspective you're coming from. "The US is hurt in diplomatic relations" is bad for some, good for others.

None at all. I'm the one arguing that we don't know whether it is a net good or bad.

Much like throwing pennies off the top of the Empire State Building, though, uncertainty about whether something will have positive or disastrously negative consequences is generally a good argument against doing it.

What evidence is there that informants no longer trusting US handlers is a bad thing ?