[Grammar] For now, reporting live, this has been the Lakitu Bros.

[kadioguy]

“Good afternoon. The Lakitu Bros., here, reporting live from just outside the Princess's castle. Mario has just arrived on the scene, and we'll be filming the action live as he enters the castle and pursues the missing Power Stars. As seasoned cameramen, we'll be shooting from the recommended angle, but you can change the camera angle by pressing ↑, →, ↓, ← Buttons. If we can't adjust the view any further, we'll buzz. To take a look at the surroundings, stop and press ↑ Button. Press (A) Button to resume play. Switch camera modes with the (R) Button. Signs along the way will review these instructions. For now, reporting live, this has been the Lakitu Bros.”

—Lakitu Bro., Super Mario 64

https://www.mariowiki.com/Lakitu_Bros.

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1.
What does it mean by using the present progress tense in the blue part? Does that mean that the Lakitu Bros. have been reporting live from the beginning until now?

2.
a. For now, reporting live, this has been the Lakitu Bros.

b. For now, reporting live, this is the Lakitu Bros. (my sentence)

What different effects exist between (a) and (b)?
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(In the real game) (At 1:18-1:45)

 

[emsr2d2]

Yes, the use of "has been" shows that the reporting is (for the time being) over.