Fair point that I do not know how USC defines "plans" but I would be surprised if such an established school had low employment, at least relative to the many other schools in the LA area.
I have the detailed survey results for UCSF from my year which are not published, and show exact employer totals. The few who answered "other" included special situations like post-graduation travel plans as a purposeful delay in seeking employment (must be nice), and actual employment that did not fit other categories e.g. hired directly into a pharmacy administration position after graduation. People have also gotten jobs very shortly after the survey deadline. I don't recall it being on graduation day, some may also have still been waiting on Phase II match results etc. Also keep in mind that 10% of the survey responses would be only about 12 people in a class of ~122 at the time.
It would be nice to track employment 1-2 years out for those doing residencies, and I do not know yet if the school attempts that or just checks in at later intervals. Perhaps it is in the published literature somewhere how much residency affects overall employment? However, I can say that from what I know the vast majority of my class has secured jobs. I am sure that I could comb through social media in 15 minutes and give you close to an exact percentage, but would this change your thoughts on anything?
Residency helped me not just to get a job in general, but to get a job that I wanted despite having little connection to the area I chose to move to. I even turned down a non-clinical job offer in the area since I had multiple interviews for clinical positions completed. I was able to be choosy on purpose, and some of my delay was from the process of moving itself, so please do not assume I am making excuses for a short gap in employment. I do not regret residency or would consider myself underemployed for that period. It opened doors and I can't say that I could have taken this path if I had gone to another school with much lower match rates.
I agree with you that the job market is overall tougher, but in CA many jobs especially in hospitals or other advanced roles require a residency. It really is a path to employment in this market.