Someone said it was mentioned on Sims VIP - but I have not been there to check.
I haven't heard anything as the ones that say they plan to change it said they were going to start a new save or upgrade the weather machine as I guess that allows you to change the weather without starting a new save. What have you heard is happening? Ive changed mine like 3 or 4 times and i havent experienced a problem yet. I'm glad I started with what I planned to keep - 28 days. Do you guys know you need to start a new game to change the toggles on the Seasons panel from what I'm hearing? Must be how they got around the issue with toggles in Sims 4 breaking saves.