I found it really odd that LoMM was not available at the launch of Mod 16, as it had been available on Preview (and the alpha playtest server before that). Sure, it had some bugs, but really...it was in no worse shape than the rest of M16.
So, why no LoMM?
Well, I have a theory. Unfortunately, if I am correct, I guess I cannot get it confirmed, as those who know the truth would probably not be allowed to confirm it. Of course, if I am totally and utterly wrong, they could probably say so.
Here is my guess: Someone at WotC saw something in LoMM that they didn't like, and basically went: "This is our intellectual property, and you cannot do this". What it was, I have no idea, maybe some dialogue, maybe Halaster had the wrong beard color or whatever - at any rate - they presumably have a veto over things like this. So, Cryptic had to go back and fix whatever the issue was to keep WotC happy, which meant delaying LoMM until May 9th.
(just to be clear...this is pure speculation - I have no inside information whatsoever).
Make NWO great again, please....