In my experience, most holos pulled from WOTC packs fall into the 8 or 9 grade range. Silvering, factory lines, bad centering, corner whitening, and ragged edges are the most commonly found flaws for pack-fresh cards. These are minor flaws that don’t really impact the appearance of the card in a significant way, and will at worst bring the card from a 10 to an 8 (maybe a 7 if a combination of these flaws are present).
I can’t say I’ve ever gotten a damaged holo from a pack, but I’ve seen it happen, the worst case scenario being indents and bent corners. Nasty stuff.
I have a couple No Symbol holos that I pulled with dirty fingerprints and odd marks all on the back side. It’s almost like the sheet they were from was the bottom sheet of the stack that got slid across multiple surfaces and touched directly by hand.
I still shudder a bit when I think about the base set blister pack I opened recently that had a Charizard with a ton of factory holo scratches and a big ol’ dent in the back of the card.
30+ pack fresh Fossil Aerdactyls I think around 8 or 9 got gem mint rest 9s and weeded out a few that would get 8 or below. Highly depends on the set for example Neo Rev holos are atrocious while Neo Destiny is much better.
I bought a ton of no symbol Jungle packs from a guy who had a weird singles case directly from WOTC, 50% holos I got 10s, and the rest looked like the holo sheet got dragged across a gravel road. I had half get 8s and even some 6s.