"Delegate everything" - delegation is hugely important. But not everything, obviously, as a team lead your responsibility as "transparent umbrella" cannot be delegated.

It also sounds like he is talking mostly about external projects. For internal projects, you really do serve as a shield. One project, I spent my first months teaching the internal customers that they were not allowed to talk to my people. They had become accustomed to telling individual developers "I want feature X", which cause total chaos.

I stood between the customers and my developers - at the beginning, sometimes literally blocking the office door - and said: my team, my job, you talk to me.