The person "throwing" the software has 0 obligation to any potential or actual users of said software. Just the act of making it available, even without any kind of license, is already benevolent. Anything further just continues to add to that benevolence, and nothing can take away from it, not even if they decide to push a malware-ridden update.

There is obligation to a given user only if it's explicitly specified in a license or some other communication to which the user is privy.