I don't believe it does. For sure the new 'PAINLESS' BLACK POWDER BORE CLEANER by Wipeout claims it is not.
Here's one from Barrett that specifically claims to be ammonia free: Heavy Bore Cleaner
Precision shooters I know have been using Sweet's for years to attack copper buildup. I think the ammonia was what made it so effective at that task. I was taught it was not a problem unless left to contaminate brass. It can harm brass, no doubt. But a good general cleaning and lube afterward will prevent that.