[Animats]

No, the air in the tube matters, at least in Musk's original design, which has the pod running on a very thin air cushion. In practice, most designs are maglev, for which a hard vacuum is best.

[e2e8]

But that amount of air may not matter too much for the points discussed in the video which have to do with strength, seals, etc.

[TeMPOraL]

That, and AFAIR original design had a system to pull the air from the front to the back, thus lowering the drag while reducing the need for lower air pressure.