You will still have to work on your "catch" The video you are watching is talking about the mindset of current elite sprinters in the world.
To be able to swim extremely fast like Cielo and Bousquet do with a straight arm pull, one must have exceptional body strength, super healthy shoulders and a coach to watch over them to make sure they aren't dropping their elbow.
Having seen underwater footage of both athletes, they set a "high catch" but the arm isn't bent like what swimmers have been taught for years. So, no, they don't drop their elbows.
Unless you are swimming a 50/100 free at high level in the sport, you would be better served developing a "high elbow catch"