I just noticed mine @1PM EST. I like it!It was part of the last updates; here's the relevant part of the release notes under the mobile section:
- We added new, lush tree visuals, which will be appearing in newly started games, instead of a wide, empty field. This feature will not be available immediately after the update, and it will be tested among a number of players first, before it's being added to all accounts.
...and all the Fall colours + fallen leaves during the Fall event.It isn't just newly started games, though. My chapter 14 Beta city now has this too.
But yeah, before this the only change is when the snow is added during winter.