This entire article is stupid. Consultants have throughout all of history coached their employees on presentation in office environments and communicating in an influential way. Every generation working for a consultant will have experienced this. This has nothing to do with GenZ or returning to the office.
And self-employed consultants, such as I have been for decades, have immediately found out the necessity and benefits of dressing and communicating with clients in a professional way. That applies equally, whether the client is a C-level executive, a military officer, or a room full of programmers wearing jeans with holes in them.