He was sort of doing this, but video was recorded somewhere in 2017 I think, and owner couldn't update the device even if he wanted to do it, because he didn't know the password.
You were probably referring to the PIN code, not a password. The guy in the video forgot his PIN. More precisely, his friend, the professional poker player who has a photographic memory, forgot a 5-digit PIN code 
. Posting this video on Youtube now in 2022 is just a free marketing campaign for Kingpin more than anything else...
I agree. He sounds like an interesting guy I would definitely want to talk to. Plus he seems willing to help people who find themselves in a similar situation. He said that at the end.Not possible for regular humans, but I bet smart guys and hackers like Kingpin, with all their gadgets will find some way to do it again. 
If he can make a Trezor glitch and go into debug mode, I am sure he could find a way to trick the device into accepting an older firmware.