I would say maybe let's not be too critical now? Keep in mind they have already announced features with packs that were actually included in the base game, like the bill system overhaul, firefighters and ladders were announced with EL, the reputation system and terrain manipulation were announced with GF and lot traits were announced with CL. Maybe (and most likely) this feature WILL come to the base game.
I think the lifestyle feature might work kinda like hobbies in Sims 2. There will be some classes of activies (16 to be precise) like music activies, snow activities, food activities, crafting activites, nature activies and so on, and the more your sim does a certain type of activity, they will gain more "points" until this type of activity will becomes their lifestyle, and they'll maybe have whims related to it, unlock new interactions and such.
The sentiment feature, I think should work kinda like in Sims 2 as well, where if two sims fight, they will be angry with eachother for a reasonable amount of time, and won't do friendly interactions until they're over it. Likewise, if two sims do something very happy and remarkable together (like going on a honeymoon or climbing a mountain together) they'll have easier relationship gain and maybe some new interactions during that time.
I don't know. Hopefully I'm not dreaming too much.
