Since I have never played a MUVE, I again interviewed my oldest son for this. According to him these online, interactive games are “pretty fun with lots of cursing and violence to a degree depending on the game.” A person “can get lost in the game.” He was taking about games such as MineCraft, Call of Duty, etc.
If the above description is accurate for all MUVEs, I really don’t see the benefit of any library having this. The only upside for MUVEs is to draw in the youth or user to the library so that they may experience the other aspects of the library while there and then come back later to utilize those other programs.