You are correct I am NOT familar with their processes, I am however, very well aware of what is realistically achievable for a team that works full time on a title and that one year is nothing in games development, whether you have a team of 800+ people or 20+.
So while you are correct, I am missing some pieces, I have enough experience to tell you the core mechanics will not change in a year when they still have a game to ship. Will there be adjustments? Yes, will there be a big rework of already existing mechancis? Simple anwser; no. Why? Because 1 year is not enough time.
The examples you gave are very likely about 2-7 lines of code, depending on how complicated their direction engine is. As for the initiative, while that would be more involved, its not a big change, certainly nowhere near the level of change required to even get close to other PC adaptions of 5e.
I can give you the reasoning behind my interpretation of the CM situation. I have worked at two very big companies with extensive CM departments (dev studios of 400+ people + support personal). If a company predicts there is going to be backlash, they have prepared statements. If not, they tend to react within a week because usually everything longer than that affects public relations and thus the bottomline. So either, their team is not sure how to answer yet, or they lack resources. Or and I admit that freely, I could be wrong about this. However, in regards to the time needed to overhaul the core mechanics, I will maintain my position.
Do you class the sort of changes people are generally suggesting as “core mechanics” though? Some might regard them as “core D&D rules”, but I don’t think many are fundamental parts of the game code. Things like whether something is an action or a bonus action, whether jump triggers reactions, whether all classes should get thieves bonus actions, whether rangers and their familiars can both attack, whether cantrips cause surface effects, whether you can heal by eating an entire cheese wheel as a bonus action, etc, etc. None of these sound like weeks of programming effort, assuming the programming isn’t a convoluted mess.
As for the fact they aren’t replying to individual requests one week into early access, personally I wouldn’t expect them to. They went into early access specifically to get feedback and to see what might be improved, but they didn’t know what requests would be most popular or whether those requests fit with their vision of the game. So they’ll keep quiet at least until they’ll discussed internally and decided what they might be willing to change and what the priority list is. They’ll let us know when they are good and ready, or maybe just drop the first update without warning.
By all accounts DOS 1 and 2 changed significantly in early access based on feedback.