I understand that it’s not new. But announcers seem to be picking up on it a lot more. Mark Jackson asked last game whether he was coached to do that, as if he hadn’t noticed it before.
I think folks are commenting on it because it has been incredibly effective.
As others have noted, this isn't really some 'new' technique, it is a drag-screen to set a seal. The Cs have been using it heavily all year and Theis is really, really good at it. They also run it with their other bigs, but Theis is the best at it, probably because he's the most versatile offensively of our various bigs, is very quick to cover space and can do the most variations (because he's a threat to 'pop' as well as roll).
Coach Daniel put out a nice YouTube analyzing the 'double drag' variation back in December:
https://www.youtube.com/watch?v=U3INe9hPAEkThe seal he puts on Jokic at about the 5:45 mark is beautiful, but the video really shows all the different types of action that is possible off that basic play.
I believe the Cs have gotten even better at this play since that video was put together.