The description is misleading. What made the OS create a new keychain was resetting their login password, not the failed password attempts.

(The login keychain is encrypted using the user's password, so it's reasonable to create a new one when the password is changed - otherwise, you end up in a situation where applications constantly pop up prompts for a password the user doesn't know every time they try to access the keychain, e.g. to load saved passwords in Safari. I've seen this happen on older versions of macOS and it's positively infuriating.)