The law doesn't seem to make a distinction about who initiated the relationship, only the nature of it. And the existence of organized/moderated subreddits is definitely an "integral part of the employer's business."

New York law uses five factors to determine if someone is an employee. Reddit is fine on several points: the degree of control exercised by the employer over the workers and the permanence or duration of the working relationship. Being a moderator of a sub-reddit doesn't entail anything other than creating the sub-reddit, which anyone can do. In addition, there is no requirement for spending time moderating that sub-reddit. This is different from Stack Exchange.

I would agree that’s true for most smaller subreddits, but I'm pretty sure the Reddit admins have a non-trivial amount of interaction with the mods of the largest and most central subreddits. I'd also agree that if this went before a court, I would expect it to find that the mods did not qualify, but the fact that the law seems vague enough to require clarification by a court is itself a problem.

There is a fuzzy difference between how sites Reddit and Stack Exchange operate, but if Stack Exchange is violating labor laws, what change to Reddit might move it across that fuzzy line? It puts a site like Reddit in an odd position where involving themselves more directly in the moderation of their own site, in terms of requirements for subreddits and mods, tools or directions/expectations for how communities are moderated, etc, could move them into a position of violating those laws.

Seems it would destory the business model entirely then. If Reddit (the company) had to pick and choose which subs to support and pay the moderators, it would be a far less useful and interesting place….which is kind of the point of raising the question on SE, I guess.