I wouldn't mind an option to adjust time speeds, if they really are planning for 1 day = 3 seconds in the release game. That translates to 1 month = ~90 seconds and 1 year = ~18 minutes. One hour of gameplay would translate to over 3 years in-game. With many animals, that wouldn't matter at all. But with any species with a shorter lifespan... you could see an entire animal's lifetime fly by in just a couple hours of playing. To a point, that's fine I guess. But I remember back in the day playing Zoo Tycoon 2, when I had finally built a very large extensive zoo, I would simply get rid of all of my animals like the peacocks and gazelle simply because I got tired of them crapping out babies every few minutes and then dying after like an hour of owning them (assuming I bought them vs they were born in my zoo... born ones lived like 2 hours).
In my opinion, the ideal game would give me the option to adjust the way time flies. Early on in the game when I'm still building everything from scratch and I don't have much, I don't want the time to fly by like nothing. I don't want to see my animals dying of old age while I'm just starting to build my third or fourth exhibit. Heck, I don't really even want animals to start having babies super fast. Otherwise I get so caught up in building the rest of my zoo, I lose emotional attachment to my earlier exhibits because they're on like generation 10 already and I stopped naming them forever ago because I ran out of ideas and stopped caring about them. But in the later game when I have most everything I want the way I want it, then I'll care more about long-term maintenance. That's when I'd want to see more breeding. That's when I feel like I'd have the time to enjoy actually witnessing my animals live out their lives. Perhaps my issue is that I just get so caught up in building and well, simulating, that I just forget to take the time to stop and enjoy my creation once in a while XD