Seasons SimGuru/Maxis-Sourced Info

CAS

https://twitter.com/TheSims/status/1002596967510208512

Seasonal CAS:

Make sure to change Sims into their summer outfits or they’ll risk overheating. - blog post

https://twitter.com/SimGuruEmory/status/1001556577063649281
https://twitter.com/SimGuruEmory/status/1001578096032534528

https://twitter.com/SimGuruGrant/status/1001876911407034369

Outerwear?
https://twitter.com/SimGuruGrant/status/1001876911407034369
https://twitter.com/SimGuruGeorge/status/1007905462509920256

From the Livestream*:

• Hot and cold weather outfits are coming with the patch (even though I don't really see the point of them without Seasons, maybe for storytelling purposes or to avoid conflicts for people who don't have Seasons installed).
  
• Swimwear for toddlers is also coming with the patch, but if you don't have Seasons only the diaper will be tagged as swimwear (again, I don't really see the point since kiddie pools probably come with Seasons not the patch, but maybe they did that for integration with future packs or again to avoid conflicts for people who don't have Seasons installed).
  

Custom Content
https://twitter.com/SimGuruEmory/status/1004122379109330944
https://twitter.com/SimGuruGrant/status/1004475291022966784

*Thanks to @lexus20 for Livestream info