Hoi,
You ask for understanding but there is so little to go on. When you say overuse, what does that mean? Obviously it was to be expected that there is growth in the use of the Wikidata Query Service, and the SPARQL endpoint. They are recently added to Wikidata and they have proven to be really popular.
What is the expectation of the growth of the Wikidata Query Service, and the SPARQL endpoint? What preparations have been made to accommodate this? What will happen when this growth is 1000 times bigger than what you expect?
The reason why I am asking is that there are organisations that would like to make use of Wikidata. They will rely on Wikidata for their service and they are considering how they can be of service to our editors and readers.
As a statement of fact with a validity of say a week your message is fine. After this week it is really important to know and experience what you deliver to make the existing growth happen without resorting to the throttling the current use of our services.
Thanks,
GerardM