I would note, though, that the idea of transpiration cooling has been around for a long time. It’s just never been implemented. But I guess what he’s saying has never been proposed before is the structure also serving as heat shield.
[Update a while later]
New Glenn has been redesigned. Looks like the upper stage is expendable.
Looks like they were inspired in part by Falcon 9. It’s interesting that we’re starting to see spacecraft designs converging, as aircraft designs did in the thirties.