There is a way to know when simulator has the latest hotfix applied? mainly due to azerite traits that blizz likes to nerf every week. for example the nerf to streaking stars trait on 24/09.
If I’m not sure I’ll look at the Theorycraft Wiki and see which values are being used.
There is a “Change Log and Updates” area in the UI. A new entry should be added there when the simulations are done. According to another topic regarding the same question, they are doing an update on some tanking strategies at the same time: http://forums.askmrrobot.com/t/update-on-25th-of-sep/5008