I was reading through the comments and noticed that some people also lost their households and lots etc. Try looking for your Sims files on your computer/laptop (on a mac its found in the Electronic Arts folder, might be the same for PC). If you click on it there should be two folders. One that says Sims4 and another that says Sims4 Legacy Edition. In each of those folders there should be another file labeled Tray (you might have to scroll down a bit to find it).
If you copy paste the contents from the Sims 4 Tray folder into the Legacy Editions Tray folder it will transfer over a chunk of your content when you start the game up next. (don't forget to restart origin when your done).
I think it's definitely worth a try if you find that your content is missing after the update. (idk what all is saved in the Tray file tbh but if it doesn't work you can always delete or undo what you copy pasted and it would be like it never happened- so definitely worth a try)
I managed to get back the things I posted through a different method suggested by Crinrict (on pg1) because another Simmer was kind enough to download my work from the gallery on their end and transfer me the file over the internet through a website called "Media Fire" to paste directly into my tray folder. I currently have everything I've posted so I can vouch for that method. (although the first method would probably be easier to try).
I hope everyone is able to get as much as their stuff back as possible, even if your too upset to play anymore I think it'll still feel a lot better just to know that you have it.