I know there are a lot of people that wish a lot of the state of decay year one stuff should be added to state of decay 2 mostly the guns but also the vehicles such as the station wagon and military truck and military uniforms as well.
On another note the story aspect of state of decay 2 for me even though I know the undead labs team is split between state of decay 2 and state of decay 3 and is working hard on trying to implement story as well as other content to make the state of decay 2 more entertaining but what I personally think lacks in any sort of special nostalgia are the vehicles as I mentioned earlier the station wagon and military vehicle from the first game and I'm aware that it is harder to make new stuff and vehicles especially cause I'm working on my own game solo and it's heavily inspired by state of decay 2 and 1 but also has inspiration from other zombie based titles games but the vehicles have been harder for me to implement because trying to balance how much storage the game takes up and also make sure that the game can run without freezing every second.
Another thing I fined that lack is the customizability of outfits even though making outfits that are between as little parts as possible such as clothes, hats and backpacks is the easiest and less consuming of time and resources but it would bring more life to the game if you had the option of choosing the shirts, pants, shoes, hats, glasses, facial hair, ect, . But something I could say would also add character to the characters you play as is the customizability of the characters background like job before the outbreak. With weapons even though a lot of people don't care for how their guns look I would say add standard factory grade paint and an attachment system would be nice even if it will be implemented in Sod3.
Even with all that has happened in the past years I hope that I can continue to support this ever-growing game and community!