Just returned from 6 nights, we had been there 4 years ago so did Aulani pre and post Covid. We had an amazing time and I think if we hadn't been there before would not have thought of Aulani as any different - its still a beautiful, amazing resort.
If your family is vaxxed the process is fairly easy. You can go to the Safe Travels site any time before the trip and upload your vax cards. From SFO they checked us and gave us bracelets before departure, that will vary by airport, but having those makes the entrance process extremely easy. When we got to Aulani they checked cards again and gave us all black bracelets. They did not ask for ID for my 12 year old (I brought his passport just in case) in fact most places assumed he was under 12. My 10 year old tested before (she's only had time for 1 shot) and still got a black band due to age - I'd expect that to change after the holidays when 5-11s can be fully vaxxed. Other than that we didn't need to be checked again at Aulani, only when going to a museum or restaurant away from the resort.
The beach is renting stand up paddle boards and boogie boards. Rainbow reef is open, in fact the fish feeding apparently sells out super fast, snorkeling does not. Masks indoors so from your room to the elevator to outside ( <5 minutes) then off. I saw nearly 100% compliance in the resort and off site.
The one difference I felt (and maybe bc we had a studio instead of a 1bdr) is fewer food options. The ABC store across the street had plenty for us, in fact I could have skipped going to Safeway, we prefer to eat Hawaiian food anyway.