Is there any new info on the Save Data bug?

Personally, I do run into occasional issues/bugs, but nothing has ruined my saves in this manner you seem concerned about. If I were you I would not live/play in fear of this... or let it stop you from playing. However, I must say that I would always, always recommend that you keep several backup saves of your game, just in case of any number of problems. I keep several saves that are recent, plus I keep several that are not as recent. I save them on my computer, preferably in two places... one on the computer or your backup drive, then one in an additional location, perhaps a thumb drive or second backup/external drive. I actually do this with all files that I would be sad to lose or that are important. For myself, I actually save the entire 'The Sims 4' folder from Documents > Electronic Arts > The Sims 4. At the least you will want to save/backup the following folders: Saves, Tray, Mods, Screenshots, Recorded Video, as you could add these folders to a new game install if yours became corrupted. There is a bit more info here if you want to know what those folders contain, etc.