Reddit's explanation (from an admin account, /u/ModCodeofConduct) is that 'encouraging the submission of sexually explicit (18+) content in previously safe-for-work spaces' counts as 'engaging in malicious conduct' that breaks the
Moderator Code of Conduct.
The same admin account was also caught quietly flipping the NSFW subs back to SFW status. So this is clearly just about getting back that monetization.
There's no need to pay the mods when they're already doing it for free, with many more willing to take their place. Some of the mods do it for power, but I would hope most do it for their love of good discussion and their community.
If it really comes down to it, I wouldn't be surprised at all if the Reddit admins just kick out all the protesting mods, finding replacements will likely be pretty easy.
The mods of several large subreddits were all kicked out, leaving the subreddits unmoderated. Multiple of these removed mods are also locked out of their accounts.
Apparently they implemented 'seven safety systems to help it return to the surface', but whether those actually worked is questionable.
It doesn't exactly inspire hope to read that one of these 'systems' was to have the passengers 'tilt the sub by moving to each side of it releasing weights held in place on each side'.
The guys at Milvus raised a total of $113M according to Crunchbase, second only to Pinecone, which is funded by a16z. You're not going to highlight the main competitor of one of your portfolio companies.