Were Red Four and Red Eight present at the Battle of Yavin?

Question

At the climax of Star Wars: Episode IV – A New Hope, Red Squadron is the group of X-wing pilots part of the attack on the Death Star.

At the start of the attack the pilots report their status:

Red Leader: All wings report in.

Red Ten: Red Ten standing by.

Red Seven: Red Seven standing by.

Biggs Darklighter: Red Three standing by.

Porkins: Red Six standing by.

Red Nine: Red Nine standing by.

Wedge Antilles: Red Two standing by.

Red Eleven: Red Eleven standing by.

Luke Skywalker: Red Five standing by.

Red Leader: Lock S-foils in attack position.

Now we already know why the pilots report in out of order and why Luke is "Red Five". However, reading through the list again I notice that Red Four and Red Eight do not report in. Why is this; were they lost during the Battle of Scarif and not replaced before the Battle of Yavin, were they unable to fly the mission for some other reason, was it an editing/production decision?

Was there a Red Four and Red Eight and if so, where were they during the Battle of Yavin?

Answer 1

Red Four, yes; Red Eight, yes, but …

Red Four and Red Eight each have entries in Wookiepedia.

In the movie, Red Four is credited as “Jack Klaff - Red Four (John D.)” and was the first Rebel pilot killed in the battle. In the script and the novelisation he was Blue Six, Luke was Blue Two - Red squadron was the Y-wing squadron that did the first attack run. The designations were changed in post but too late to have Alan Dean Foster change the book.

Red Eight’s first appearance as a call sign is in the 2015 video game Star Wars Battlefront. Red Eight was named as Zal Dinnes in the short story Duty Roster who dies during the Battle of Yavin.

The anthology in which Duty Roster appears is canon but it is knowingly inconsistent with other works. You know, like real history is.

The retcon is not inconsistent with the movie assuming everything that happened to Red Eight happened off screen.

Answer 2

According to the short story 'Duty Roster' in the 'Star Wars: From a Certain Point of View' anthology; Branon and Zal flew as Red Four and Eight respectively.

As for why you didn't hear them sign in: I refer you to the very answer you yourself linked to in your question; the check-in was edited for pacing and dramatic effect. Making the audience sit through all thirty pilots checking in would have been needlessly dull. We really don't need an in-universe explanation since what the audience is shown is always going to be subjective. It's an adventure story, not a documentary.