Armageddon MUD was based on Dark Sun, like a straight rip of the IP way back in the day. Someone sold them out to WOTC who sent a cease and desist but they never followed up and all Armageddon MUD did was remove some of the IP specific races like halflings and kanks and the like.
I would imagine as long as you only provided SRD information in the helpfiles and encouraged players to have books or digital books you'd be set. Also non-profit yada yada. I mean streamers are entitled to run through licensed modules and content for no fees except the cost of buying the material thus allowing them to broadcast it.
But the old that's just my opinion, no one really knows, time sink vs risk etc etc. I get it. Just my 2 cents.