Elite levels are meant as additional level content for players who have completed both the available World Map levels and the currently available Hero levels. If you have Elite levels available, the levels can be accessed on the World Map.
These Elite levels will be available while you are waiting for new levels to open.
When new levels are released each week, the option to play Elite levels will be removed until you complete the last available level again.
In other words, whenever you are waiting for new levels, Elite levels are offered as an option for you to play so that you can keep completing our events.