If you refuse to actually read the findings of Feist (or at very least the wikipedia page [1] that does a good job of summarising the ruling and it's implications), then I'm not really sure I can be bothered to repeat and expand upon the above explications of how it applies to this case.
To quote wikipedia:
The ruling has major implications for any project that serves as a collection of knowledge. Information (facts, discoveries, etc.) from any source is fair game, but cannot contain any of the "expressive" content added by the source author. That includes not only the author's own comments, but also their choice of which facts to cover, which links to make among the bits of information, the order of presentation (unless it is something obvious like alphabetical), evaluations of the quality of various pieces of information, or anything else that might be considered the author's "original creative work" rather than mere facts.
The key part for this case being "Their choice of which facts to cover".
> You have cited no factual source for your wild, speculative claims that Wardle's partner was deemed to have a copyright interest in the word list or transferred such interest to NYT.
How can I? As I said, nobody has seen the paperwork, so there is no factual source that says either way. And it really doesn't matter. What does matter is the possibility that NYT do have the correct paperwork.
There is no way to be sure about the possibility that the wordlist might be copyrighted (or not) and who actually owns the copyright, short of a full court case on this exact issue.
I'm not a lawyer. But I suspect any intellectual property lawyer who was asked about this topic would advise their client against using the offical wordle wordlists. Not because they know for sure, but out of caution.
Besides, it's really not that hard for someone to derive their own wordlist from base principles (as you have pointed out above). We are only talking about a few days of effort if they take the same approach of manual classification and the piece of mind for closing a possible legal venerability is (in my opinion) more than worth it.
[1] https://en.wikipedia.org/wiki/Feist_Publications,_Inc.,_v._R....