There is already a FR that could accomplish this (and more): Vault Health Dashboard - All Reports should do automatic lookups and alerts. Basically, instead of having a separate detection mechanism, leverage the existing reports to do the heavy-lifting. “Change at-risk password”, does not tell me much, but “Is on Reused passwords report” would be immensely helpful.
And, bonus, as new reports are added or improvements are made, the alert/warning would inherit them: