It looks like it could potentially fix the micromanaging nightmare that The Sims 3 was if TS4 still keeps the open world gameplay.
The only time I really enjoyed the open world of The Sims 3 was when I was playing as a single sim. With that sim I would explore the world, collect things, find hidden locations, play the more interactive jobs in Ambitions, and generally actually the the gameplay that was unique to TS3 that TS2 didn't have... Buuuut, then once that sim got married, had children, had their deadbeat brother move in... Suddenly, the open world became a huge chore to have to deal with. While the game had no loading screens, there was no way the game could keep everything in a world loaded all at once, so trying to bounce around town to keep tabs on an entire family cause laggyness, stuttering, and really ugly texture loading to get thrown up in my face. On top of that, it was super annoying! Having to wait for the camera to fly all the way up into the sky, when fly over the sim I'm selecting, and then fall back down to focus on them was pretty damn flow breaking and made it harder to control everyone. I wish when selecting a sim the camera could just instantly teleport to where they are, but I guess that would make the texture loading even worse.
Eventually I would just give up entirely. I'd end up playing TS3 the way one would play TS2; your family would just stay in their homes, all day, every day, only leaving to go to work/school. The only way to make the open world bareable was to download a mod that made time progress slower, which was nice, but also kinda screwed up job and skill gain speeds making the game almost too easy.
Welp, guess I'll keep my eye on this and hope it's not as disappointing as TS3. I loved TS1 and 2, I hope this can bring back some of the old charm lost in TS3.