The sharp decline in coaches in Naismith and other worlds has nothing to do with FreeHD and everything to do with the NO-potential system.
Season 34 was the first under the NO-Potential system. The Season 36 jump in coaches was because the season started during the NCAA Tournament - that jump happens every year.
I am just ending Season 36 in Naismith that had the fewest coaches than in any season I have seen since I joined Naismith in Season 19. My conference will have only two returning coaches for Season 37. Nearly every world that has rolled over has over 200 SimAI teams.
217 job openings in World 3, DIII
264 job openings in World 9, DIII
203 job openings in World 2, DIII
218 job openings in World 1, DIII
270 job openings in World 10, DIII
WiS ruined HD, especially, DIII with the NO-potential system and everyone has to pay the price.