I trust the simulations mentioned in the article take this into account, but the grandparent is right that this is not it all obvious from the video. In fact the video shows very leven flight motion while the wings are brought up, which absolutely would not be the case.
The key bit is right at the end, showing launch in real time. There is no descent for lack of lift because there is no time for it to happen in. While the animal is still rising from the jump, the wings swing out and take up the load, in a fractional second.
It would be terrifying to have it happen toward you, even as it swept over.