We're about to get a GS pup but we already have two cats 3 and 5 years old. Will a GS get along with them?
The breed has nothing to do with it.
When you bring the puppy home for the first time, introduce your cats one at a time and let them sniff each other for awhile, so they cah get to know each other. Teach the pup not to chase them or play with them roughly. If you train him when he's young, he'll grow to get used to them, and they'll all be happy!

We brought out golden retriever puppy home when we had 4 cats, and they all grew to love her!
I agree. The breed is less important than how the owners introduce the pets and how they set further relationship. It's like asking whether boys or girls make better kids. Everything depends on the parents!
I have a 2 year old German Shepherd pup who absolutely adores my 2 cats! He's still a little boisterous for the cats' taste, but a couple of swats on the nose from the cats, and/ or a stern word from me always sets him straight. As long as you maintain that the pup is to be gentle, I can't see why your new fur baby wouldn't get along with your cats.
I had 3 dogs (including a German Shepard). Guess who was the boss-the cat. I used to laugh every time she swatted them on the nose if they thought they were tougher than her.
my dog just had pups it was a four year trek to breed the dog i wanted i had to search but when i found a malamute cross sharpae i went into action in other words i waited and waited then success she was old enough but i had the same worry is it normal well i just read on some pages that’s its very normal in Alaskan malamutes but only one the first of the kalamae breed male he has got blue eyes and guess what everyone thinks they are human eyes and well a rumour has now started stupid people but when I find who started the rumour well I’m going to sue the shit out of them