Still, there would be different weather and conditions:
cold, ice, frost, condensation (visible exhalation) etc.
Summer isn’t just winter without snow. 
Yes, thats right. Also: missing leaves…
another thing is seasonal food. According to the flowers in the livestream we are between mai and july. This means: the apple on the table is more than 6 months old. He looked to fresh…
If they could get seasonal effects in, I’d be very much up for it. Having to simulate several different sets of AI and world behaviour might be too time-consuming to design/program though so I wouldn’t be too upset if they decide not to.