At the time of writing, it appears that VH-MMC is staying for at least the night.
UPDATE! On Thursday 7 January, VH-MMC departed Emerald Airport and returned to the Sunshine Coast.
While also on Wednesday 6 January, Brescon (Toowoomba) Beech B200 King Air VH-XDW was flying up to my local Clermont Aerodrome from Toowoomba-Wellcamp but was forced to divert and land at Emerald Airport due to weather around Clermont. VH-XDW was then due to return to Wellcamp but was forced to divert to Chinchilla and then Kingaroy Aerodromes.
UPDATE! Early on Thursday 7 January, VH-XDW departed Kingaroy for Wellcamp.