Completing world quests with the buff active still awards only 75 reputation with Midnight faction renown.
Rather than a bug, this seems to be an intentional change, as the World Quest bonus events in The War Within similarly didn't grant increased renown with the The K'aresh Trust and we learned earlier this year that the Darkmoon Faire reputation buff also no longer applied to Midnight Renown, making it seem as though Blizzard doesn't want certain events to fast-track renown.
Or not...
In some ways this is good, as players traditionally used all sorts of tricks to delay completion, align turn-ins, or manipulate alts for the Faire and other buffs to maximize their gains, instead of progressing through the game naturally. On the other hand, it also defeats the entire purpose of this weekly event, joining a growing list of other outmoded weekly events that are now largely ignored by players.
Both Magisters' Terrace and the Midnight version of The World Awaits are available this week, so players still have an opportunity to earn a good bit of extra renown with the faction of their choice, and each world quest still awards 30 Voidlight Marl, which is probably even more useful! Unfortunately, the Thorm'belan world boss world quest does not contribute, at least not while in a raid group.
Silvermoon Court Renown GuideAmani Tribe Renown Guide
Hara'ti Renown GuideThe Singularity Renown Guide
