I'm not sure how much of the old system is merely disabled -- still there, under the hood -- or just gone now. I've been told that the wetness and wind code was completely gutted. Haven't looked myself so I don't know. But In practical terms it doesn't really matter. Those features have been deprecated and no longer affect gameplay.
Regardless, modders have already recreated those features for v2.0. So, you know, whatever. It is what it is. Shame that stuff was removed from vanilla, but I don't play unmodded anyway.
Supposedly one of the devs posted on Discord that they want to reimplement temperature at some point in the future. So maybe that'll happen.