I don't mind him doing the drills. Football is a game of habit. Under pressure we all default to habitual responses. So doing drills to create new, better habits, makes sense.
What concerns me is the idea I'm meant to be impressed by seeing this.
Is this new? If so, why is it new? The player was bought years ago. Has he not been working on his touch and overlapping in that time? Is it only now that we have a new coach that he feels that he needs to put in work, outside of the training the club forces him to do, to improve?
If this is not new then why are we only seeing it now? Moreover, where is the evidence that this isn't new from what Wan-Bissaka has been doing on the pitch? Why have we not seen a clear upwards improvement in Wan-Bissaka's game over the past couple of years? This is the same lad who got sent off against Young Boys last season because his second touch is a tackle.
I remember when Andy Cole signed for United. He was so limited as a player. Just a guy for the box. However, over time his game came on massively. He became an all round forward who could contribute to build up. Who had fantastic hold up play. Who could drift outside of the 18 yard box, maybe even score a chip or a scissor kick. The improvement in his game was obvious, you didn't need him putting out videos to show what he'd been doing.
Honestly, find the Wan-Bissaka video bizarre.