There is no default logging that will record the creation of a new threshold profile or new notifier rule.
There is no log for this, but you can run a rest call and see what listed once a week, or once a month, so that you can monitor what is added.
curl
http://your_da:8581/rest/eventprofilescurl
http://your_da:8581/rest/eventrulesthese to calls will show you whats there, and also lists the create times.
(remember to replace your_da with the name of your data aggregator)