What do people think about this version of the policy?
It does not contain any definition of a "mixer" (unless it will stay as it is in the first post).
Does anyone think that it's worse than the original version, and if so, why?
I think it is very similar, because the problem is not about "Starting Jan 1, 2024" paragraph, this is fine (so, in that case, both versions are good enough for me). The problem is in "Definition of a mixer", because if anyone will try to bypass the rules, then that person will say: "It is not a mixer, it is just a CoinJoin, just a Lightning Network, just a Full-RBF, just Monero, or just not-yet-listed-but-allowed-x".
Are there any possible improvements (which wouldn't totally undermine the whole thing)?
It depends. If the purpose is to ban certain mixers (those, which could be seized), while leaving other mixers unaffected, then it is fine, people will just switch from one kind of mixers to other ones (or start advertizing casinos or other things, to be 100% safe).
I wonder if there is a need to explicitly create the list of allowed and disallowed things. Because I guess the biggest issue will be with those users, who will not be 100% sure, if something is allowed or not. And then, some of them may be disappointed, that a certain mixer is allowed ("Why you allowed it theymos, it is a mixer!") or not ("Why you rejected it theymos, it is just a CoinJoin!"). But, I also guess that kind of list could also cause more harm than good, so I don't know, how to handle it properly, and I am happy, that I am not responsible for making such decisions.