I have thought the exact same thing. If the game was online there would have been no need for a robust AI because all interactions with other sims would be you interacting with another RL person controlling that other sim. That's why I'm hoping that EA is truly not crazy enough to try it again with TS5, otherwise we're going to end up with Sims 4.5 when it has to be scrapped because it failed.
Time will tell and I hope the same thing as you. Sadly my expectations are that they might be marketing to console based play where they need to go big, flashy and current rather than the small intricacies PC fans like myself expect might be the way forward. I anticipate more brand collaborations, online play and a greater focus on goal based play. Like I mentioned I think the life simulation genre needs to expand for fans to feel satisfied.
