Personally, I'd love the maps from the first to just be ported over, I don't think it would take that much work to do and even with them all being the same biome, they're still new maps.
New maps are a lot of the things that the game ought to have, and several of the old maps are workable for smaller options to play with.
A "Returning Favorites" pseudo-DLC would be great, an update that adds back in things from the first game we don't have if you own the original and the right DLCs there.
12 maps for use, 3 hybrids, and perhaps the storm protection buildings...if you're someone who already bought them there, you get rewarded, if you didn't, well, it's a reason to go back and get them.
Perhaps adding in a new feature, letting you build a park and "abandon" it, and the game runs through a lot of things and degrades a lot of things in the park, adds a lot of foliage, and can adjust the dinosaurs existing there with chances of having reproduced, escaped the area, or been wiped out...possibly diseases, injuries, or other things over that time. Perhaps setting some capture missions for the escaped ones.