Due to the amounts of flights in and out of the island each day the amount of tourists is pretty well capped
...except that they can just add more flights.
Please read this report:http://www.mdpi.com/2071-1050/8/11/1093/pdf
Tourism has been increasing at a 20% annual rate on Rapa Nui, and it has not leveled off.
From the document I linked to:
"...an estimate by Figueroa et al.  shows that, taking into
account the current growth in tourist numbers, by 2020 tourist arrivals are expected to range from
92,000 to 118,000; and, by 2030, this range could be between 168,000 and 215,000 tourists."
Here is a graph of the latest tourism numbers:
Since I was there in 2007, tourism has more than doubled and in a few years will have tripled.