Life Day and the planet Kashyyyk first appeared in comics in the Star Wars Newspaper Comics #19 by Russ Manning on July 15, 1979!
Ha. That was a newspaper strip and written out of continuity when Lucas scrapped the Holiday special
Lucas called the movies gospel and everything else gossip. These were as canon as all the other comics at the time which was “kinda.”
I need to do more digging for the first Life Day mention and Kashyyyk appearance in traditional comic book.
It was a recent Star Wars Adventures that would get first appearance in comics.
I use Fandom pages a lot- Marvel, DC and Wookiepedia- to find 1st appearances of characters. They are implying the Light Day #1 comic will be the first comic book appearance of High Republic era Wookie Jedi Burryaga Agaburry. It isn’t outright stated but implied. On the page they have for Burryaga, it lists his appearances and it list all the novels he has been mentioned in and then lists ‘Light Day 1‘ in the list of his appearances.
Yeah, I usually don’t list upcoming firsts on WookyWiki.com until day of release. August to November leaves a lot of room for a character to pop up in another HR title. I fully expect Life Day #1 to be his first, though.
I wonder if some of those other people in the background there will be big eventually in the grand scheme of High Republic. That may mean High Republic #1 May become an even bigger key issue than we already think it’s going to end up being.