This paper can confirm it (page 4/8: 400 m² for 2 MW). But theory and tests of pumping kites give far lower values, due to the downwind motion and both the time and the power consumption during the reel-in phase. In theory a 200 m² kite with L/D ratio = 4 would generate about 285 kW during reel-out (power) phase with a wind speed of 10 m/s, so an average power of about half.
And tests on “hydra” (14 m²) with 10 m/s wind speed result in an average of 5.75 kW (table 8, page 44 of https://repository.tudelft.nl/islandora/object/uuid:56f1aef6-f337-4224-a44e-8314e9efbe83/datastream/OBJ/download). A 200 m² wing with the same features would give an average of about 80-100 kW.