The article certainly doesn't make it sound like they let in anyone:

""" Last year, 70,000 people attempted the online qualification test. 20,000 completed the test, and of those, 4,000 were invited to spend four weeks in Paris doing an intensive project that had them working upwards of 100 hours a week on various coding challenges. In the end, 890 students were selected for the school’s inaugural class, which began in November, 2013. """