Of course they brought him back from that a handful of times before the Disney take over. Marvel Comic’s Star Wars 81 had him claw his way up from the pit to be rescued by Jawas. He had amnesia and the Jawas originally thought he was a droid with all that armor. In the end the sandcrawler was seen plummeting into the pit (though even as a kid I was like - well shit, he could get out of that.)
And then more officially he was brought back Dark Horse Comics Dark Empire. From there he was featured in several other books.
So yeah - no surprise he is officially back again - and I think they did it in a fantastic way.
No, not at all. Not the TV shows, at least. Are you already a fan? Then you will squee at the characters you already know about showing up. New to the show? In the Mandalorian they do a good job of introducing even new viewers to the universe and characters. Never heard of such and such character? You don’t need to know their previous adventures, they tell you who they are and why the are important to this story.
My kid has seen the original trilogy - but doesn’t really remember it well. But she has enjoyed The Mandalorian with me. So I think that shows that the TV shows are good stand-alones, and honestly, are bringing new viewers into the Star Wars universe.
I understand the hesitancy to get into something already established and feeling you missed something. At least with The Mandalorian, I would proceed with out worrying too much about that. I assume The Book of Boba Fett will be treated similarly.

