In general if you don't get one within a few weeks of going UR, then if you *do* get in, the path is likely to be unpredictable (like, if you submitted in Oct, you might suddenly get one in the middle of Feb in a trend that makes no sense), or a WL-->Admit, otherwise the odds become fairly low. So, by that point, best to just like....stop following the trends and watching the threads for signs of JR1 movement and just focus on other things in life.
Yes, basically this. A long delay generally means you aren't among the top applicants, but you could very well be in the "wait and see" applicant pool (which makes sense for a school doing rolling admissions). At least that is how it went last year.