During the last panel they mentioned being almost 'feature complete', someone with more knowledge about game development could weigh in, but to me that sounds like the window to change most of the major issues that have come up on these forums is mostly closed. A Day/Night Cycle or changing how long rests work, doesn't seem like an aspect of polishing.
What that might mean for the next patch or for the two-year anniversary is a release that has many more of the changes we haven't seen that they've finally settled on or it could mean very little as we go into the pre-release era.
There might be more aspects of the story that they open up as they want more people to try and break the game, but that sounds really optimistic.
Since there isn't any governing bodies or real standardization for product/software life cycle development, unfortunately the term can be somewhat nebulous. Though my experience with software is outside of videogames - so maybe there's more standardization there.
In my experience - it varies by company. Feature complete can literally mean the features are exactly going to be what they are now, and all updates are just bug fixes. OR, it could mean while the list of feature is locked, for each feature, the UI, the specific integration and implementation within the feature is still being worked on. And depending on the company and their process, you can have feature complete even prior to the Alpha release - though in my experience feature complete usually leads to the beta.
To be extra confusing, how features are actually categorized can be completely up to the company too. I.e. some of us might deem the "5e reaction system" a feature. Whereas for Larian's feature list, reactions might fall under a much broader category like "combat" that has been accounted for since day 1. For all we know, the feature list that Larian has is a ton of back-end stuff the average player doesn't even think about. As much as we like to nitpick over specific D&D rule and mechanics in the game, in the grand scheme of a fully functional video game with millions of lines of codes and interaction, these things are actually pretty small.
Remember though, what we see in the EA is not the most current internal-build, but basically an outdated mirror of the game that has been stripped down and updated at a far slower pace. So unless someone has access to the internal Larian build you can't really determine what is feature complete includes.
Now I don't want to give the impression that means I expect a lot of things are still coming - my point is that we basically have absolutely no idea and terms like "feature complete" doesn't mean much for outsiders since we don't have any proper points of references.
If I had to guess, I personally wouldn't bet on a Day/Night cycle. I'm not too sure if we'll even get an anniversary updates because the last update was actually relatively recent.
Patch 6 was October 14, 2021
Patch 7 was February 15, 2022 (124 days later)
Patch 8 was July 7, 2022 (142 days later)
We are currently only 65 days since Patch 8. October 6 would be 91 days since Patch 8.
If we take the average of the last 2 gaps in patches, the next update would come Nov 17.
