When a repeating event without an end date is created, infinite events will not be created immediately
The following amounts of Event will be created and then a new event will be created each time the repeat frequency is reached:
Calendar max recurrence days = 65
Calendar max recurrence weeks = 10
Calendar max recurrence months = 13
Calendar max recurrence years = 3
In other words, for a weekly repeating event, there will only ever be 10 future weeks of events created and each time a new week is elapsed, a new event will be created, ensuring that there is always 10.
The same goes for all frequencies, but you should replace 10 with the values above.