Frankly I don't know that I would play it but you made some good points @Stormsview
I think as long as people could have their single player game there shouldn't be a problem to add an online dimension. I think the policing is the big problem but ... that's another kettle of worms.
I think in time we will have something like this (not sure if its the Sims) but it is probably the best possibility for a more family friendly possibility here. Especially with limitations on broader servers.. as in no mods or limited mods and age requirements.
I don't know if it's possible with the Sims 4 but maybe it is.. I can see it extending it's run overall also. Big changes possibly being made at times especially for optimization.
Another thing it could possibly do is continue to lend financial support to the game (this one if it's possible) when basically all the packs that can be created have been created. People would have to either buy private servers or probably pay some amount to visit franchise run ones. I could see it working. Not how overall since there are many ways it could go but yeah..
I'd give it a try there are some friends I've made along the way I'd enjoy hanging out with.