I have had this happen about a grand total of 3 times since the update. It seem that the fear of dead end job has about a one in ten chance to happen when returning home from work regardless of any other condition. So your Sim could literally be in the perfect mood, get promoted then be mortified of there job not presenting future opportunity. I also think it is dumb you can only conquer fears if the bubble appears beside you sim in the bottom left corner. The bubble dose not seem to present itself unless you enter moodlets. To add fuel to the fire Regain passion seems to have something like a two in three chance of working. I have had a sim stuck with this fear for about a week in game because he keeps failing to regain passion regardless of what moodlets or interactions he has. In a nut shell fears are very broad and don't actually interact with other systems. Fears get triggered by broad actions rather then the context of what is going on with your Sim and the kind of life they are living. Honestly I feel like Fears are weighing down systems like moodlets and taking focus away from them.
As for wants...Wants seem to have a VERY low chance to appear and are only triggered by entering moodlets under specific circumstances. For example a Soulmate asperation sim get flirty with there partner they may then want to do a specific romantic action with that sim. I am not sure if wants are way more common if you have the newer DLCs and honestly I am not willing to spend the money to find out. Unlike the moodlets associated Whims, wants are way to contextual and far to infrequent to even feel like they are important. So they are sort of the opposite of fears. They have potential to work in correlation with moodlets but they just don't trigger often enough. The sad thing is most of the ones I have experiences were basically more particular versions moodlet associated Whims. It makes me wonder why there are so infrequent and so few when it is just a watered down Whim.