the subreddits do not really work like that. subreddits with same or similar themes pop up all the time but there is an element of randomness and passionate moderation that makes people flock to a particular one, which gains critical mass and become self sustaining.
starting a subreddit as a paying employee would be a process of repeated trial and error until something sticks.
promoting a mod to an employee introduces a profit motive that very easily ruin a subreddit.
taking over a subreddit causes immediate exodus.
the best content comes from organic discussion and careful moderation that guides the direction of the community. I don't think they can control the narrative of subreddit that have openly rebelled but I guess we'll see.